diff --git a/src/components/ApiTest/index.vue b/src/components/ApiTest/index.vue
index 22c2f5d..ac3ed06 100644
--- a/src/components/ApiTest/index.vue
+++ b/src/components/ApiTest/index.vue
@@ -1955,7 +1955,6 @@
         </a-button>
         <a-button
           size="small"
-          type="primary"
           :loading="isLoading"
           :disabled="isLoading"
           @click="sendRequest"
diff --git a/src/components/CustomLeftMenu/index.vue b/src/components/CustomLeftMenu/index.vue
index 15aca29..8ff2962 100644
--- a/src/components/CustomLeftMenu/index.vue
+++ b/src/components/CustomLeftMenu/index.vue
@@ -416,7 +416,7 @@
                   >
                     <a-dropdown
                       trigger="click"
-                      :popup-max-height="250"
+                      :popup-max-height="false"
                       @select="handleActionSelect"
                     >
                       <a-button
@@ -460,7 +460,7 @@
                       </span>
                       <a-dropdown
                         trigger="click"
-                        :popup-max-height="250"
+                        :popup-max-height="false"
                         @select="handleActionSelect"
                       >
                         <a-button
diff --git a/src/components/InterfaceDetail/index.vue b/src/components/InterfaceDetail/index.vue
index 78af87e..3667508 100644
--- a/src/components/InterfaceDetail/index.vue
+++ b/src/components/InterfaceDetail/index.vue
@@ -25,7 +25,7 @@
     buildSmartFillResult,
   } from '@/utils/curlToInterfaceFill';
   import { useTabRowCounts } from '@/utils/useTabRowCounts';
-  import { FormKvPlaceholderOptions, ParameterType } from '@/constants/itfxEnums';
+  import { FormKvPlaceholderOptions, ParameterType, FieldPosition } from '@/constants/itfxEnums';
   import {
     flattenTreeTableRows,
     getTreeTableFlatRows,
@@ -440,6 +440,7 @@
   function validateKvParamRows(rows: any[], label: string): string | null {
     const seen = new Set<string>();
     for (const row of rows || []) {
+      if (isCommonParamRow(row)) continue;
       const name = String(row?.name ?? '').trim();
       if (!name) return `${label} 存在未填写参数名的行，请补全或删除空行`;
       const key = name.toLowerCase();
@@ -583,6 +584,138 @@
     () => props.showQuery && !isDownstreamMode.value,
   );
   const showHeaderTab = computed(() => isDownstreamMode.value && props.showQuery);
+
+  /** 下游：服务商公共参数按位置回落到 Query/Header/Body（只读置灰） */
+  const inheritedCommonParams = ref<any[]>([]);
+  const inheritedCommonParamsLoading = ref(false);
+
+  function normalizePositionList(row: any): number[] {
+    const list = row?.fieldPositionList;
+    if (Array.isArray(list) && list.length) {
+      return list.map((x: any) => Number(x)).filter((n: number) => Number.isFinite(n));
+    }
+    const fp = row?.fieldPositions;
+    if (typeof fp === 'string' && fp.trim()) {
+      return fp
+        .split(',')
+        .map((x) => Number(x.trim()))
+        .filter((n) => Number.isFinite(n));
+    }
+    if (Array.isArray(fp)) {
+      return fp.map((x: any) => Number(x)).filter((n: number) => Number.isFinite(n));
+    }
+    return [];
+  }
+
+  function commonParamsForPosition(position: number) {
+    return inheritedCommonParams.value.filter((row) =>
+      normalizePositionList(row).includes(position),
+    );
+  }
+
+  const inheritedQueryParams = computed(() =>
+    isDownstreamMode.value ? commonParamsForPosition(FieldPosition.Query) : [],
+  );
+  const inheritedHeaderParams = computed(() =>
+    isDownstreamMode.value ? commonParamsForPosition(FieldPosition.Header) : [],
+  );
+  const inheritedBodyParams = computed(() =>
+    isDownstreamMode.value ? commonParamsForPosition(FieldPosition.Body) : [],
+  );
+
+  function isCommonParamRow(row: any) {
+    return !!row?.__fromCommonParams;
+  }
+
+  function stripCommonRows<T extends Record<string, any>>(rows: T[] | undefined | null): T[] {
+    return (Array.isArray(rows) ? rows : []).filter((r) => !isCommonParamRow(r));
+  }
+
+  function filterCommonFromActionRows(actions: any) {
+    const filterRows = (arr: any[]) =>
+      (Array.isArray(arr) ? arr : []).filter((r) => !isCommonParamRow(r));
+    return {
+      insertRecords: filterRows(actions?.insertRecords),
+      removeRecords: filterRows(actions?.removeRecords),
+      updateRecords: filterRows(actions?.updateRecords),
+    };
+  }
+
+  function toCommonKvRows(list: any[]) {
+    return (list || []).map((row, idx) => ({
+      __fromCommonParams: true,
+      disableEdit: true,
+      id: `common-kv-${row.id ?? idx}`,
+      name: row.fieldName || '',
+      value: row.fieldValue || '',
+      description: row.description || '公共参数',
+      __commonParamId: row.id,
+    }));
+  }
+
+  function mergeCommonKvRows(ownRows: any[] | undefined, commonList: any[]) {
+    return [...toCommonKvRows(commonList), ...stripCommonRows(ownRows)];
+  }
+
+  async function applyKvTableWithCommon(
+    tableProps: { data: any[] },
+    tableRef: { value?: { reloadData?: (rows: any[]) => any } },
+    ownRows: any[] | undefined,
+    commonList: any[],
+  ) {
+    const next = mergeCommonKvRows(ownRows, commonList);
+    tableProps.data = next;
+    await nextTick();
+    tableRef.value?.reloadData?.(next);
+  }
+
+  async function remergeInheritedCommonIntoKvTables() {
+    if (!isDownstreamMode.value) return;
+    await applyKvTableWithCommon(
+      queryTableProps,
+      queryTableRef,
+      stripCommonRows(queryTableProps.data),
+      inheritedQueryParams.value,
+    );
+    if (showHeaderTab.value) {
+      await applyKvTableWithCommon(
+        headerTableProps,
+        headerTableRef,
+        stripCommonRows(headerTableProps.data),
+        inheritedHeaderParams.value,
+      );
+    }
+    await applyKvTableWithCommon(
+      bodyFormTableProps,
+      bodyFormTableRef,
+      stripCommonRows(bodyFormTableProps.data),
+      inheritedBodyParams.value,
+    );
+    refreshTabCounts();
+  }
+
+  async function refreshInheritedCommonParams() {
+    const spId = Number(props.serviceProviderId);
+    if (!isDownstreamMode.value || !Number.isFinite(spId) || spId <= 0) {
+      inheritedCommonParams.value = [];
+      await remergeInheritedCommonIntoKvTables();
+      return;
+    }
+    inheritedCommonParamsLoading.value = true;
+    try {
+      const res: any = await getFixedParameterGetFixedParameterList({
+        serviceProviderId: spId,
+      });
+      const data = res?.data || res || [];
+      inheritedCommonParams.value = Array.isArray(data) ? data : [];
+    } catch {
+      inheritedCommonParams.value = [];
+    } finally {
+      inheritedCommonParamsLoading.value = false;
+    }
+    await remergeInheritedCommonIntoKvTables();
+  }
+
   const isNoneBodyContentType = computed(
     () => isDownstreamMode.value && isNoneContentType(props.basicFormData?.contentType),
   );
@@ -992,7 +1125,9 @@
         mode: 'row',
         showStatus: true,
         autoClear: false,
+        beforeEditMethod: ({ row }: { row: any }) => !isCommonParamRow(row),
       },
+      rowClassName: ({ row }: { row: any }) => (isCommonParamRow(row) ? 'row-common-param' : ''),
     },
     showIndex: false,
     data: [] as any[],
@@ -1017,6 +1152,14 @@
     data: [] as any[],
   });
 
+  watch(
+    () => [props.serviceProviderId, props.parameterMode] as const,
+    () => {
+      refreshInheritedCommonParams();
+    },
+    { immediate: true },
+  );
+
   // Query 固定配置表格（不传 height，随内容自然增高，与 Query 列表的固定高度区分）
   const queryFixedTableProps = computed(() => ({
     columns: [
@@ -1327,11 +1470,17 @@
 
   const canClearCurrentRequestTab = computed(() => {
     if (!showRequestTabClearAction.value) return false;
-    if (requestTab.value === 'query') return queryTabCount.value > 0;
-    if (requestTab.value === 'header') return headerTabCount.value > 0;
+    if (requestTab.value === 'query') {
+      return stripCommonRows(getTableFullData(queryTableRef, queryTableProps.data)).length > 0;
+    }
+    if (requestTab.value === 'header') {
+      return stripCommonRows(getTableFullData(headerTableRef, headerTableProps.data)).length > 0;
+    }
     if (requestTab.value === 'fixed') return fixedConfigTabCount.value > 0;
     if (requestTab.value === 'body') {
-      if (isBodyKvMode.value) return !isBodyKvEmpty.value;
+      if (isBodyKvMode.value) {
+        return stripCommonRows(getTableFullData(bodyFormTableRef, bodyFormTableProps.data)).length > 0;
+      }
       return !isBodyTreeEmpty.value;
     }
     if (requestTab.value === 'mappingBody') return !isMappingBodyEmpty.value;
@@ -1339,48 +1488,65 @@
     return false;
   });
 
-  // 监听 queryParams prop 变化，同步到表格数据
+  // 监听 queryParams prop 变化，同步到表格数据（并合并公共参数）
   watch(
     () => props.queryParams,
-    (newVal: any) => {
-      if (newVal && Array.isArray(newVal)) {
-        // 只在数据真正变化时才更新，避免循环
-        const currentData = queryTableProps.data || [];
-        if (currentData.length !== newVal.length || JSON.stringify(currentData) !== JSON.stringify(newVal)) {
-          queryTableProps.data = [...newVal] as any[];
-          if (queryTableRef.value) {
-            queryTableRef.value.reloadData([...newVal]);
-          }
-        }
+    async (newVal: any) => {
+      if (!newVal || !Array.isArray(newVal)) return;
+      const own = stripCommonRows(newVal);
+      const currentOwn = stripCommonRows(queryTableProps.data || []);
+      if (
+        currentOwn.length !== own.length
+        || JSON.stringify(currentOwn) !== JSON.stringify(own)
+      ) {
+        await applyKvTableWithCommon(
+          queryTableProps,
+          queryTableRef,
+          own,
+          inheritedQueryParams.value,
+        );
       }
     },
-    { immediate: true }
+    { immediate: true },
   );
 
   function syncKvTableProps(
     propList: any[] | undefined,
     tableProps: { data: any[] },
     tableRef: typeof queryTableRef,
+    commonList: any[],
   ) {
     if (!propList || !Array.isArray(propList)) return;
-    const currentData = tableProps.data || [];
+    const own = stripCommonRows(propList);
+    const currentOwn = stripCommonRows(tableProps.data || []);
     if (
-      currentData.length !== propList.length
-      || JSON.stringify(currentData) !== JSON.stringify(propList)
+      currentOwn.length !== own.length
+      || JSON.stringify(currentOwn) !== JSON.stringify(own)
     ) {
-      tableProps.data = [...propList] as any[];
-      tableRef.value?.reloadData?.([...propList]);
+      applyKvTableWithCommon(tableProps, tableRef, own, commonList);
     }
   }
 
   watch(
     () => props.headerParams,
-    (newVal) => syncKvTableProps(newVal as any[], headerTableProps, headerTableRef),
+    (newVal) =>
+      syncKvTableProps(
+        newVal as any[],
+        headerTableProps,
+        headerTableRef,
+        inheritedHeaderParams.value,
+      ),
     { immediate: true },
   );
   watch(
     () => props.bodyFormParams,
-    (newVal) => syncKvTableProps(newVal as any[], bodyFormTableProps, bodyFormTableRef),
+    (newVal) =>
+      syncKvTableProps(
+        newVal as any[],
+        bodyFormTableProps,
+        bodyFormTableRef,
+        inheritedBodyParams.value,
+      ),
     { immediate: true },
   );
   watch(
@@ -1839,13 +2005,13 @@
     tableRef: any,
     keepRow?: (row: any) => boolean,
   ) {
-    const roots = [...(getTableFullData(tableRef) || [])];
+    const roots = [...(getTableFullData(tableRef) || [])].filter((r) => !isCommonParamRow(r));
     if (!keepRow) return roots;
     const toRemove: any[] = [];
     roots.forEach((row) => {
       if (keepRow(row)) {
         if (Array.isArray(row?.children) && row.children.length) {
-          toRemove.push(...row.children);
+          toRemove.push(...row.children.filter((c: any) => !isCommonParamRow(c)));
         }
         return;
       }
@@ -1858,17 +2024,32 @@
     const tab = requestTab.value;
     if (tab === 'query') {
       await removeTableRows(queryTableRef, collectRemovableTableRows(queryTableRef));
-      queryTableProps.data = [];
+      await applyKvTableWithCommon(
+        queryTableProps,
+        queryTableRef,
+        [],
+        inheritedQueryParams.value,
+      );
     } else if (tab === 'header') {
       await removeTableRows(headerTableRef, collectRemovableTableRows(headerTableRef));
-      headerTableProps.data = [];
+      await applyKvTableWithCommon(
+        headerTableProps,
+        headerTableRef,
+        [],
+        inheritedHeaderParams.value,
+      );
     } else if (tab === 'fixed') {
       await removeTableRows(queryFixedTableRef, collectRemovableTableRows(queryFixedTableRef));
       fixedParams.value = [];
       fixedParamsHasChanges.value = true;
     } else if (tab === 'body' && isBodyKvMode.value) {
       await removeTableRows(bodyFormTableRef, collectRemovableTableRows(bodyFormTableRef));
-      bodyFormTableProps.data = [];
+      await applyKvTableWithCommon(
+        bodyFormTableProps,
+        bodyFormTableRef,
+        [],
+        inheritedBodyParams.value,
+      );
     } else if (tab === 'body' && !isNoneBodyContentType.value) {
       if (hoistedBodyArrayWrapper.value) {
         const persisted = getRequestBodyFlatParams();
@@ -1941,6 +2122,7 @@
 
   // 删除 Query 参数行
   async function deleteQueryRow(row: any) {
+    if (isCommonParamRow(row)) return;
     markDirty();
     await queryTableRef.value?.removeRow(row);
     refreshTabCounts();
@@ -1955,6 +2137,7 @@
   }
 
   async function deleteHeaderRow(row: any) {
+    if (isCommonParamRow(row)) return;
     markDirty();
     await headerTableRef.value?.removeRow(row);
     refreshTabCounts();
@@ -1969,6 +2152,7 @@
   }
 
   async function deleteBodyFormRow(row: any) {
+    if (isCommonParamRow(row)) return;
     markDirty();
     await bodyFormTableRef.value?.removeRow(row);
     refreshTabCounts();
@@ -2922,10 +3106,9 @@
     tableProps: { data: any[] },
     tableRef: { value?: { reloadData?: (rows: any[]) => void } },
     rows: any[],
+    commonList: any[] = [],
   ) {
-    tableProps.data = rows;
-    await nextTick();
-    tableRef.value?.reloadData?.(rows);
+    await applyKvTableWithCommon(tableProps, tableRef, rows, commonList);
   }
 
   async function loadFlatListIntoTreeTable(
@@ -3022,11 +3205,26 @@
     await nextTick();
     refBasicForm.value?.setFormValue?.(nextBasic);
 
-    await reloadKvTable(queryTableProps, queryTableRef, payload.queryParams);
+    await reloadKvTable(
+      queryTableProps,
+      queryTableRef,
+      payload.queryParams,
+      inheritedQueryParams.value,
+    );
 
     if (isDownstreamMode.value) {
-      await reloadKvTable(headerTableProps, headerTableRef, payload.headerParams ?? []);
-      await reloadKvTable(bodyFormTableProps, bodyFormTableRef, isForm ? payload.bodyFormParams : []);
+      await reloadKvTable(
+        headerTableProps,
+        headerTableRef,
+        payload.headerParams ?? [],
+        inheritedHeaderParams.value,
+      );
+      await reloadKvTable(
+        bodyFormTableProps,
+        bodyFormTableRef,
+        isForm ? payload.bodyFormParams : [],
+        inheritedBodyParams.value,
+      );
       if (!isForm && !isNone) {
         mappingBodyTableProps.data = [];
         await nextTick();
@@ -3197,20 +3395,27 @@
     validateDetailParamsBeforeSave,
     captureDirtyBaseline,
     markDirty,
+    refreshInheritedCommonParams,
     isDirty: () => isDirty.value,
     getSaveSnapshot: (): InterfaceDetailSnapshot => ({
-      queryParams: queryTableRef.value?.getTableData?.()?.fullData
+      queryParams: stripCommonRows(
+        queryTableRef.value?.getTableData?.()?.fullData
         || queryTableRef.value?.xGrid?.getTableData()?.fullData
         || queryTableProps.data
         || [],
-      headerParams: headerTableRef.value?.getTableData?.()?.fullData
+      ),
+      headerParams: stripCommonRows(
+        headerTableRef.value?.getTableData?.()?.fullData
         || headerTableRef.value?.xGrid?.getTableData()?.fullData
         || headerTableProps.data
         || [],
-      bodyFormParams: bodyFormTableRef.value?.getTableData?.()?.fullData
+      ),
+      bodyFormParams: stripCommonRows(
+        bodyFormTableRef.value?.getTableData?.()?.fullData
         || bodyFormTableRef.value?.xGrid?.getTableData()?.fullData
         || bodyFormTableProps.data
         || [],
+      ),
       requestParams: getRequestBodyFlatParams(),
       mappingBodyParams: getTreeTableFlatRows(
         mappingBodyTableRef.value?.getTableData?.()?.fullData
@@ -3221,9 +3426,9 @@
         || responseTableRef.value?.xGrid?.getTableData()?.fullData
         || responseTableProps.data
         || [],
-      queryActionRows: queryTableRef.value?.getActionRows?.() || { insertRecords: [], removeRecords: [], updateRecords: [] },
-      headerActionRows: headerTableRef.value?.getActionRows?.() || { insertRecords: [], removeRecords: [], updateRecords: [] },
-      bodyFormActionRows: bodyFormTableRef.value?.getActionRows?.() || { insertRecords: [], removeRecords: [], updateRecords: [] },
+      queryActionRows: filterCommonFromActionRows(queryTableRef.value?.getActionRows?.()),
+      headerActionRows: filterCommonFromActionRows(headerTableRef.value?.getActionRows?.()),
+      bodyFormActionRows: filterCommonFromActionRows(bodyFormTableRef.value?.getActionRows?.()),
       requestActionRows: stripBodyRootFromActionRows(
         requestTableRef.value?.getActionRows?.() || {
           insertRecords: [],
@@ -3472,7 +3677,10 @@
                     placeholder="请输入参数名"
                   />
                 </template>
-                <span v-else>{{ row.name || '-' }}</span>
+                <span v-else class="kv-name-cell">
+                  {{ row.name || '-' }}
+                  <span v-if="isCommonParamRow(row)" class="common-param-tag">公共</span>
+                </span>
               </template>
 
               <template #name_edit="{ row }">
@@ -3540,13 +3748,14 @@
               </template>
 
               <template #action="{ row }">
-                <a-space>
+                <a-space v-if="!isCommonParamRow(row)">
                   <a-popconfirm content="确定删除该参数？" @ok="deleteQueryRow(row)">
                     <a-button type="text" class="row-action-btn">
                       <IconDelete />
                     </a-button>
                   </a-popconfirm>
                 </a-space>
+                <span v-else class="common-param-action">—</span>
               </template>
             </TablePro>
             </div>
@@ -3640,7 +3849,10 @@
               >
                 <template #name="{ row }">
                   <a-input v-if="isHeaderRowEditing(row)" v-model="row.name" allow-clear placeholder="请输入参数名" />
-                  <span v-else>{{ row.name || '-' }}</span>
+                  <span v-else class="kv-name-cell">
+                    {{ row.name || '-' }}
+                    <span v-if="isCommonParamRow(row)" class="common-param-tag">公共</span>
+                  </span>
                 </template>
                 <template #name_edit="{ row }">
                   <a-input v-model="row.name" allow-clear placeholder="请输入参数名" />
@@ -3671,11 +3883,16 @@
                   <a-input v-model="row.description" allow-clear placeholder="请输入描述" />
                 </template>
                 <template #action="{ row }">
-                  <a-popconfirm content="确定删除该参数？" @ok="deleteHeaderRow(row)">
+                  <a-popconfirm
+                    v-if="!isCommonParamRow(row)"
+                    content="确定删除该参数？"
+                    @ok="deleteHeaderRow(row)"
+                  >
                     <a-button type="text" class="row-action-btn">
                       <IconDelete />
                     </a-button>
                   </a-popconfirm>
+                  <span v-else class="common-param-action">—</span>
                 </template>
               </TablePro>
             </div>
@@ -3687,7 +3904,7 @@
           </div>
 
           <!-- Body KV（FormUrlEncoded） -->
-          <div v-show="requestTab === 'body' && isBodyKvMode" class="table-content">
+          <div v-show="requestTab === 'body' && isBodyKvMode" class="table-content body-kv-pane">
             <TablePro
               ref="bodyFormTableRef"
               v-bind="bodyFormTableProps"
@@ -3696,7 +3913,10 @@
             >
               <template #name="{ row }">
                 <a-input v-if="isBodyFormRowEditing(row)" v-model="row.name" allow-clear placeholder="参数名" />
-                <span v-else>{{ row.name || '-' }}</span>
+                <span v-else class="kv-name-cell">
+                  {{ row.name || '-' }}
+                  <span v-if="isCommonParamRow(row)" class="common-param-tag">公共</span>
+                </span>
               </template>
               <template #name_edit="{ row }">
                 <a-input v-model="row.name" allow-clear placeholder="参数名" />
@@ -3727,11 +3947,16 @@
                 <a-input v-model="row.description" allow-clear />
               </template>
               <template #action="{ row }">
-                <a-popconfirm content="确定删除该参数？" @ok="deleteBodyFormRow(row)">
+                <a-popconfirm
+                  v-if="!isCommonParamRow(row)"
+                  content="确定删除该参数？"
+                  @ok="deleteBodyFormRow(row)"
+                >
                   <a-button type="text" class="row-action-btn">
                     <IconDelete />
                   </a-button>
                 </a-popconfirm>
+                <span v-else class="common-param-action">—</span>
               </template>
             </TablePro>
           </div>
@@ -4597,6 +4822,46 @@
     }
   }
 
+  .kv-name-cell {
+    display: inline-flex;
+    align-items: center;
+    gap: 6px;
+    max-width: 100%;
+  }
+
+  .common-param-tag {
+    flex-shrink: 0;
+    padding: 0 5px;
+    height: 18px;
+    line-height: 18px;
+    border-radius: 3px;
+    font-size: 11px;
+    color: var(--color-text-3);
+    background: var(--color-fill-2);
+    border: 1px solid var(--color-border-2);
+  }
+
+  .common-param-action {
+    color: var(--color-text-4);
+    font-size: 12px;
+  }
+
+  :deep(.row-common-param) {
+    color: var(--color-text-3) !important;
+    background: var(--color-fill-1) !important;
+
+    td {
+      color: var(--color-text-3) !important;
+      background: var(--color-fill-1) !important;
+    }
+  }
+
+  .body-kv-pane {
+    display: flex;
+    flex-direction: column;
+    min-height: 0;
+  }
+
   // 请求方式 + 请求地址 - 符合设计规范
   .api-test-header {
     display: flex;
diff --git a/src/locale/en-US.ts b/src/locale/en-US.ts
index 158b545..0eee2a6 100644
--- a/src/locale/en-US.ts
+++ b/src/locale/en-US.ts
@@ -2514,12 +2514,12 @@ export default {
   'system.serviceProviders.dropdown.authConfig': 'Auth config',
   'system.serviceProviders.dropdown.accountManage': 'Account management',
   'system.serviceProviders.dropdown.export': 'Export',
-  'system.serviceProviders.dropdown.fixedParams': 'Common parameters',
+  'system.serviceProviders.dropdown.fixedParams': 'Common params',
   'system.serviceProviders.dropdown.delete': 'Delete',
 
   'system.serviceProviders.publish.title': 'Publish mapping cache · {name}',
-  'system.serviceProviders.publish.tip': 'After auth/provider changes are saved, remapped system interfaces must be republished to refresh the live cache.',
-  'system.serviceProviders.publish.confirmAfterSave': 'Saved. Check and publish mapping cache for this provider now?',
+  'system.serviceProviders.publish.tip': 'After auth, common params, or provider changes are saved, remapped system interfaces must be republished to refresh the live cache.',
+  'system.serviceProviders.publish.confirmAfterSave': 'Saved. Common params / config take effect online only after publishing mapping cache. Check and publish now?',
   'system.serviceProviders.publish.goPublish': 'Publish',
   'system.serviceProviders.publish.later': 'Later',
   'system.serviceProviders.publish.close': 'Close',
diff --git a/src/locale/zh-CN.ts b/src/locale/zh-CN.ts
index b812de6..6551e2f 100644
--- a/src/locale/zh-CN.ts
+++ b/src/locale/zh-CN.ts
@@ -2412,12 +2412,12 @@ export default {
   'system.serviceProviders.dropdown.authConfig': '授权配置',
   'system.serviceProviders.dropdown.accountManage': '账户管理',
   'system.serviceProviders.dropdown.export': '导出',
-  'system.serviceProviders.dropdown.fixedParams': '公共参数配置',
+  'system.serviceProviders.dropdown.fixedParams': '公共参数',
   'system.serviceProviders.dropdown.delete': '删除',
 
   'system.serviceProviders.publish.title': '发布映射缓存 · {name}',
-  'system.serviceProviders.publish.tip': '授权配置、服务商信息等变更写入数据库后，需对已映射的系统接口重新发布，线上缓存才会更新。',
-  'system.serviceProviders.publish.confirmAfterSave': '保存成功。是否立即检查并发布该服务商相关的映射缓存？',
+  'system.serviceProviders.publish.tip': '授权配置、公共参数、服务商信息等变更写入数据库后，需对已映射的系统接口重新发布，线上缓存才会更新。',
+  'system.serviceProviders.publish.confirmAfterSave': '保存成功。公共参数/配置需发布映射缓存后才对线上生效，是否立即检查并发布？',
   'system.serviceProviders.publish.goPublish': '去发布',
   'system.serviceProviders.publish.later': '稍后',
   'system.serviceProviders.publish.close': '关闭',
diff --git a/src/views/api/downstreamInterface/components/ServiceProviderInterfaceModal.vue b/src/views/api/downstreamInterface/components/ServiceProviderInterfaceModal.vue
index 7a9dc98..803f641 100644
--- a/src/views/api/downstreamInterface/components/ServiceProviderInterfaceModal.vue
+++ b/src/views/api/downstreamInterface/components/ServiceProviderInterfaceModal.vue
@@ -547,6 +547,8 @@
     confirmLeaveUnsaved: (options?: { content?: string }) =>
       interfaceDetailRef.value?.confirmLeaveUnsaved?.(options) ?? Promise.resolve(true),
     captureDirtyBaseline: () => interfaceDetailRef.value?.captureDirtyBaseline?.(),
+    refreshInheritedCommonParams: () =>
+      interfaceDetailRef.value?.refreshInheritedCommonParams?.(),
   });
 
 </script>
diff --git a/src/views/api/downstreamInterface/comps/Entering.vue b/src/views/api/downstreamInterface/comps/Entering.vue
index 07f6a73..155a602 100644
--- a/src/views/api/downstreamInterface/comps/Entering.vue
+++ b/src/views/api/downstreamInterface/comps/Entering.vue
@@ -7,7 +7,6 @@
     getServiceProviderChangeAuthInterface,
     getServiceProviderGetAuthInfo,
   } from '@/api/ServiceProviderInterface/serviceProviderAuth';
-  import { getDictionaryGetList } from '@/api/ApplicationServices/dictionary';
   import { addModalForm, configData, interfaceId } from './data';
   import { $baseConfirm } from '@/utils/confirm';
   import FormPro from '@/components/FormPro/index.vue';
@@ -234,66 +233,18 @@
     key: number;
   };
 
-  const dictionaryLoaded = ref(false);
-  const loadingDictionary = ref(false);
-  const restaurants = ref<RestaurantItem[]>([]);
+  const restaurants = ref<RestaurantItem[]>([{ value: '$FromAccount', key: 1 }]);
 
-  async function loadDictionaryData() {
-    if (dictionaryLoaded.value || loadingDictionary.value) {
-      return;
-    }
-
-    loadingDictionary.value = true;
-    try {
-      const response: any = await getDictionaryGetList({ type: 'ParameterPlaceholder' });
-      let data: API.EnumCacheEntry[] = [];
-      if (Array.isArray(response)) {
-        data = response;
-      } else if (response && Array.isArray(response.data)) {
-        data = response.data;
-      } else if (response && response.data) {
-        data = Array.isArray(response.data) ? response.data : [];
-      }
-
-      const options = data.map((item: any, index: number) => ({
-        value: String(item.value || ''),
-        key: item.key || index,
-      }));
-
-      const defaultOptions = [
-        { value: '$FromAccount', key: 1 },
-        { value: '$TimeStamp', key: 2 },
-      ];
-
-      const allOptions = [...defaultOptions];
-      options.forEach((option: RestaurantItem) => {
-        if (!allOptions.find((item) => item.value === option.value)) {
-          allOptions.push(option);
-        }
-      });
-
-      restaurants.value = allOptions;
-      dictionaryLoaded.value = true;
-    } catch {
-      restaurants.value = [
-        { value: '$FromAccount', key: 1 },
-        { value: '$TimeStamp', key: 2 },
-      ];
-    } finally {
-      loadingDictionary.value = false;
-    }
-  }
-
-  function loadAll() {
-    return [
-      { value: '$FromAccount', key: 1 },
-      { value: '$TimeStamp', key: 2 },
-    ];
+  function filterOption(inputValue: string, option: any) {
+    return (
+      !inputValue ||
+      String(option.value || '')
+        .toLowerCase()
+        .includes(String(inputValue).toLowerCase())
+    );
   }
 
   onMounted(async () => {
-    restaurants.value = loadAll();
-
     if (configData.interfaceCode) {
       oldVal.value = configData.interfaceCode;
       await nextTick();
@@ -312,15 +263,6 @@
     }
   });
 
-  function filterOption(inputValue: string, option: any) {
-    return (
-      !inputValue ||
-      String(option.value || '')
-        .toLowerCase()
-        .includes(String(inputValue).toLowerCase())
-    );
-  }
-
   function deleteRow(row: any) {
     tableRef.value.removeRow(row);
   }
@@ -354,8 +296,8 @@
             v-model="record.value"
             :data="restaurants"
             allow-clear
+            placeholder="请选择或输入 $FromAccount"
             :filter-option="filterOption"
-            @focus="() => { if (!dictionaryLoaded && !loadingDictionary) loadDictionaryData(); }"
             @select="(val) => (record.value = val)"
             @change="(val) => { record.value = val; }"
           />
diff --git a/src/views/api/downstreamInterface/comps/FixedParameterConfig.vue b/src/views/api/downstreamInterface/comps/FixedParameterConfig.vue
new file mode 100644
index 0000000..b8f45e5
--- /dev/null
+++ b/src/views/api/downstreamInterface/comps/FixedParameterConfig.vue
@@ -0,0 +1,406 @@
+<script lang="ts" setup>
+  import { ref, computed, nextTick } from 'vue';
+  import { useI18n } from 'vue-i18n';
+  import useModal from '@/components/ModalPro/useModal';
+  import ModalPro from '@/components/ModalPro/index.vue';
+  import SelectPro from '@/components/SelectPro/index.vue';
+  import { getDictionaryGetList } from '@/api/ApplicationServices/dictionary';
+  import {
+    getFixedParameterGetFixedParameterList,
+    postFixedParameterMaintainParameter,
+  } from '@/api/ParameterServices/fixedParameter';
+  import { IconDelete, IconPlus } from '@arco-design/web-vue/es/icon';
+  import { $baseMessage } from '@/utils';
+
+  defineOptions({
+    name: 'FixedParameterConfig',
+  });
+
+  const emit = defineEmits<{
+    (e: 'saved', payload: { id: number; name?: string; code?: string }): void;
+  }>();
+
+  const { t } = useI18n();
+  const [register, { openModal, setModalProps }] = useModal() as any;
+
+  const serviceProviderId = ref(0);
+  const serviceProviderMeta = ref<{ id: number; name?: string; code?: string } | null>(null);
+  const loading = ref(false);
+  const saving = ref(false);
+
+  type FixedRow = {
+    __rowKey: string | number;
+    id?: number;
+    fieldName?: string;
+    fieldValue?: string;
+    fieldPositionList?: Array<number | string>;
+    description?: string;
+  };
+
+  const tableData = ref<FixedRow[]>([]);
+  const originalById = ref<Map<number, FixedRow>>(new Map());
+  let rowKeySeq = 0;
+
+  const placeholderOptions = ref<{ value: string; label: string }[]>([]);
+
+  const tableColumns = computed(() => [
+    {
+      title: '序号',
+      width: 64,
+      align: 'center' as const,
+      render: ({ rowIndex }: any) => rowIndex + 1,
+    },
+    {
+      title: '参数名',
+      dataIndex: 'fieldName',
+      slotName: 'fieldName',
+      minWidth: 140,
+    },
+    {
+      title: '参数值',
+      dataIndex: 'fieldValue',
+      slotName: 'fieldValue',
+      minWidth: 180,
+    },
+    {
+      title: '位置',
+      dataIndex: 'fieldPositionList',
+      slotName: 'fieldPositions',
+      minWidth: 180,
+    },
+    {
+      title: '描述',
+      dataIndex: 'description',
+      slotName: 'description',
+      minWidth: 140,
+    },
+    {
+      title: '操作',
+      slotName: 'action',
+      width: 72,
+      align: 'center' as const,
+      fixed: 'right' as const,
+    },
+  ]);
+
+  async function loadDictionaries() {
+    try {
+      const phRes: any = await getDictionaryGetList({ type: 'ParameterPlaceholder' });
+      const phList = phRes?.data || phRes || [];
+      placeholderOptions.value = (Array.isArray(phList) ? phList : []).map((item: any) => ({
+        value: String(item.value ?? item.key ?? ''),
+        label: String(item.value ?? item.key ?? ''),
+      }));
+    } catch {
+      placeholderOptions.value = [];
+    }
+  }
+
+  function normalizeRow(item: any): FixedRow {
+    const id = item?.id != null ? Number(item.id) : undefined;
+    return {
+      __rowKey: id ?? `new_${++rowKeySeq}`,
+      id,
+      fieldName: item?.fieldName ?? '',
+      fieldValue: item?.fieldValue ?? '',
+      fieldPositionList: Array.isArray(item?.fieldPositionList)
+        ? [...item.fieldPositionList]
+        : [],
+      description: item?.description ?? '',
+    };
+  }
+
+  async function loadList() {
+    if (!serviceProviderId.value) return;
+    loading.value = true;
+    try {
+      const res: any = await getFixedParameterGetFixedParameterList({
+        serviceProviderId: serviceProviderId.value,
+      });
+      const data = res?.data || res || [];
+      const list = (Array.isArray(data) ? data : []).map(normalizeRow);
+      tableData.value = list;
+      const map = new Map<number, FixedRow>();
+      list.forEach((row) => {
+        if (row.id != null) {
+          map.set(row.id, {
+            ...row,
+            fieldPositionList: [...(row.fieldPositionList || [])],
+          });
+        }
+      });
+      originalById.value = map;
+    } catch {
+      tableData.value = [];
+      originalById.value = new Map();
+      $baseMessage('加载公共参数失败', 'error');
+    } finally {
+      loading.value = false;
+    }
+  }
+
+  async function init(input: number | { id: number; name?: string; code?: string }) {
+    const id = typeof input === 'number' ? input : Number(input?.id);
+    if (!Number.isFinite(id) || id <= 0) {
+      $baseMessage('请先选择服务商', 'warning');
+      return;
+    }
+    serviceProviderId.value = id;
+    serviceProviderMeta.value =
+      typeof input === 'number'
+        ? { id, name: undefined, code: undefined }
+        : { id, name: input?.name, code: input?.code };
+
+    setModalProps?.({
+      title: `${t('system.serviceProviders.dropdown.fixedParams')}${
+        serviceProviderMeta.value?.name ? ` - ${serviceProviderMeta.value.name}` : ''
+      }`,
+      showFooter: true,
+      okText: '保存',
+      confirmLoading: false,
+    });
+    openModal();
+    await nextTick();
+    await loadDictionaries();
+    await loadList();
+  }
+
+  function handleAddRow() {
+    tableData.value.push({
+      __rowKey: `new_${++rowKeySeq}`,
+      fieldName: '',
+      fieldValue: '',
+      fieldPositionList: [],
+      description: '',
+    });
+  }
+
+  function handleDeleteRow(record: FixedRow) {
+    tableData.value = tableData.value.filter((r) => r.__rowKey !== record.__rowKey);
+  }
+
+  function positionsEqual(a?: Array<number | string>, b?: Array<number | string>) {
+    const aa = [...(a || [])].map(String).sort();
+    const bb = [...(b || [])].map(String).sort();
+    if (aa.length !== bb.length) return false;
+    return aa.every((v, i) => v === bb[i]);
+  }
+
+  function rowChanged(curr: FixedRow, orig: FixedRow) {
+    return (
+      String(curr.fieldName ?? '') !== String(orig.fieldName ?? '') ||
+      String(curr.fieldValue ?? '') !== String(orig.fieldValue ?? '') ||
+      String(curr.description ?? '') !== String(orig.description ?? '') ||
+      !positionsEqual(curr.fieldPositionList, orig.fieldPositionList)
+    );
+  }
+
+  function buildItems() {
+    const items: any[] = [];
+    const currentIds = new Set<number>();
+
+    for (const row of tableData.value) {
+      const name = String(row.fieldName ?? '').trim();
+      if (!name) continue;
+
+      const payload = {
+        fieldName: name,
+        fieldValue: row.fieldValue ?? '',
+        fieldPositionList: row.fieldPositionList || [],
+        description: row.description ?? '',
+      };
+
+      if (row.id == null) {
+        items.push({ ...payload, options: 1, id: undefined });
+        continue;
+      }
+
+      currentIds.add(row.id);
+      const orig = originalById.value.get(row.id);
+      if (!orig || rowChanged(row, orig)) {
+        items.push({ ...payload, options: 3, id: row.id });
+      }
+    }
+
+    for (const [id, orig] of originalById.value.entries()) {
+      if (!currentIds.has(id)) {
+        items.push({
+          id,
+          fieldName: orig.fieldName,
+          fieldValue: orig.fieldValue,
+          fieldPositionList: orig.fieldPositionList || [],
+          description: orig.description,
+          options: 2,
+        });
+      }
+    }
+
+    return items;
+  }
+
+  async function onModalSave() {
+    if (!serviceProviderId.value) return false;
+
+    const emptyName = tableData.value.some((r) => !String(r.fieldName ?? '').trim());
+    if (emptyName) {
+      $baseMessage('请填写参数名', 'warning');
+      return false;
+    }
+
+    const names = tableData.value.map((r) => String(r.fieldName ?? '').trim().toLowerCase());
+    if (new Set(names).size !== names.length) {
+      $baseMessage('参数名不能重复', 'warning');
+      return false;
+    }
+
+    const items = buildItems();
+    if (items.length === 0) {
+      $baseMessage('暂无变更需要保存', 'warning');
+      return false;
+    }
+
+    saving.value = true;
+    setModalProps?.({ confirmLoading: true });
+    try {
+      await postFixedParameterMaintainParameter({
+        serviceProviderId: serviceProviderId.value,
+        items,
+      });
+      $baseMessage('保存成功，如需生效请去发布', 'success');
+      emit('saved', {
+        id: Number(serviceProviderId.value),
+        name: serviceProviderMeta.value?.name,
+        code: serviceProviderMeta.value?.code,
+      });
+      await loadList();
+      return true;
+    } catch {
+      $baseMessage('保存失败', 'error');
+      return false;
+    } finally {
+      saving.value = false;
+      setModalProps?.({ confirmLoading: false });
+    }
+  }
+
+  defineExpose({ init });
+</script>
+
+<template>
+  <div class="fixed-parameter-config">
+    <ModalPro
+      :width="920"
+      :title="t('system.serviceProviders.dropdown.fixedParams')"
+      :loading="loading || saving"
+      @register="register"
+      @ok="onModalSave"
+    >
+      <div class="fixed-parameter-body">
+        <a-alert type="info" :show-icon="false" class="modal-form-tip">
+          配置当前服务商的公共参数，供其下接口共用。路径：修改 → 保存 → 发布映射缓存后才对线上生效。
+        </a-alert>
+
+        <div class="table-toolbar">
+          <div class="toolbar-left">
+            <a-button type="primary" class="app-btn-primary-soft" size="small" @click="handleAddRow">
+              <template #icon><IconPlus /></template>
+              新增
+            </a-button>
+          </div>
+          <div class="toolbar-right">
+            <span class="row-count">共 {{ tableData.length }} 条</span>
+          </div>
+        </div>
+
+        <a-table
+          size="small"
+          row-key="__rowKey"
+          :columns="tableColumns"
+          :data="tableData"
+          :loading="loading"
+          :pagination="false"
+          :bordered="{ cell: true }"
+          :scroll="{ y: 420 }"
+          class="fixed-parameter-table"
+        >
+          <template #empty>
+            <div class="empty-tip">暂无公共参数，点击「新增」添加</div>
+          </template>
+          <template #fieldName="{ record }">
+            <a-input v-model="record.fieldName" allow-clear placeholder="请输入参数名" />
+          </template>
+          <template #fieldValue="{ record }">
+            <a-auto-complete
+              v-model="record.fieldValue"
+              :data="placeholderOptions"
+              allow-clear
+              placeholder="请选择或输入参数值"
+              :filter-option="
+                (inputValue, option) =>
+                  !inputValue ||
+                  String(option.value || '')
+                    .toLowerCase()
+                    .includes(String(inputValue).toLowerCase())
+              "
+            />
+          </template>
+          <template #fieldPositions="{ record }">
+            <SelectPro
+              v-model="record.fieldPositionList"
+              :api="getDictionaryGetList"
+              :extra="{ type: 'FieldPosition' }"
+              :is-page="false"
+              :immediate="true"
+              :label-keys="['value']"
+              :multiple="true"
+              id-key="key"
+              placeholder="请选择位置"
+            />
+          </template>
+          <template #description="{ record }">
+            <a-input v-model="record.description" allow-clear placeholder="可选" />
+          </template>
+          <template #action="{ record }">
+            <a-button type="text" size="small" status="danger" title="删除" @click="handleDeleteRow(record)">
+              <template #icon><IconDelete /></template>
+            </a-button>
+          </template>
+        </a-table>
+      </div>
+    </ModalPro>
+  </div>
+</template>
+
+<style lang="less" scoped>
+  .fixed-parameter-body {
+    .modal-form-tip {
+      margin-bottom: 16px;
+    }
+
+    .table-toolbar {
+      display: flex;
+      align-items: center;
+      justify-content: space-between;
+      margin-bottom: 12px;
+    }
+
+    .row-count {
+      font-size: 13px;
+      color: var(--color-text-3);
+    }
+
+    .empty-tip {
+      padding: 24px 0;
+      color: var(--color-text-3);
+      font-size: 13px;
+    }
+
+    .fixed-parameter-table {
+      :deep(.arco-input-wrapper),
+      :deep(.arco-select-view),
+      :deep(.arco-auto-complete) {
+        width: 100%;
+      }
+    }
+  }
+</style>
diff --git a/src/views/api/downstreamInterface/index.vue b/src/views/api/downstreamInterface/index.vue
index 747f1fe..91ffe0e 100644
--- a/src/views/api/downstreamInterface/index.vue
+++ b/src/views/api/downstreamInterface/index.vue
@@ -18,6 +18,7 @@
     postServiceProviderImport,
   } from '@/api/interface-serviceProvider/serviceProviderImportExport';
   import ParameterConfig from '@/views/api/downstreamInterface/comps/ParameterConfig.vue';
+  import FixedParameterConfig from '@/views/api/downstreamInterface/comps/FixedParameterConfig.vue';
   import FormPro from '@/components/FormPro/index.vue';
   import TableButtons from '@/components/TableButtons/index.vue';
   import {
@@ -32,6 +33,7 @@
   import dayjs from 'dayjs';
   import { getDictionaryGetList } from '@/api/ApplicationServices/dictionary';
   import { getAppGetDropDownList } from '@/api/ApplicationServices/apps';
+  import { getFixedParameterGetFixedParameterList } from '@/api/ParameterServices/fixedParameter';
   import ServiceProviderInterfaceModal from './components/ServiceProviderInterfaceModal.vue';
   import AccountList from './comps/AccountList.vue';
   import ProviderMapPublishModal from './comps/ProviderMapPublishModal.vue';
@@ -48,6 +50,7 @@
     IconRefresh,
     IconMore,
     IconDelete,
+    IconList,
   } from '@arco-design/web-vue/es/icon';
   import { useI18n } from 'vue-i18n';
 
@@ -111,6 +114,8 @@
   const searchKeyword = ref('');
   const serviceProviderList = ref<any[]>([]);
   const selectedProvider = ref<any>(null);
+  const commonParamsCount = ref<number | null>(null);
+  const commonParamsLoading = ref(false);
   const loading = ref(false);
   
   // 接口弹窗相关
@@ -960,11 +965,63 @@
   }
 
   const accountList = ref();
+  const fixedParameterConfigRef = ref<InstanceType<typeof FixedParameterConfig> | null>(null);
 
   function accountManageClick(row: any) {
     accountList.value?.init?.(row);
   }
 
+  function handleFixedParamsWithSelect(provider: any) {
+    handleProviderSelect(provider);
+    setTimeout(() => {
+      fixedParameterConfigRef.value?.init?.(provider);
+    }, 150);
+  }
+
+  async function refreshCommonParamsCount(providerLike?: any) {
+    const id = Number(providerLike?.id || selectedProvider.value?.id || 0);
+    if (!Number.isFinite(id) || id <= 0) {
+      commonParamsCount.value = null;
+      return;
+    }
+    commonParamsLoading.value = true;
+    try {
+      const res: any = await getFixedParameterGetFixedParameterList({
+        serviceProviderId: id,
+      });
+      const data = res?.data || res || [];
+      commonParamsCount.value = Array.isArray(data) ? data.length : 0;
+    } catch {
+      commonParamsCount.value = null;
+    } finally {
+      commonParamsLoading.value = false;
+    }
+  }
+
+  watch(
+    () => selectedProvider.value?.id,
+    () => {
+      refreshCommonParamsCount();
+    },
+    { immediate: true },
+  );
+
+  function openCommonParamsFromTabs() {
+    const provider = selectedProvider.value;
+    if (!provider?.id) {
+      $baseMessage('请先选择服务商', 'warning');
+      return;
+    }
+    fixedParameterConfigRef.value?.init?.(provider);
+  }
+
+  function onFixedParamsSaved(payload: any) {
+    refreshCommonParamsCount(payload);
+    interfaceDetailModalRef.value?.refreshInheritedCommonParams?.();
+    interfaceModalRef.value?.refreshInheritedCommonParams?.();
+    askGoPublish(payload);
+  }
+
   function mapAccountClick(row: { id: any; code: any; name?: string }) {
     accountList.value?.init?.(row);
   }
@@ -1644,6 +1701,10 @@
           <IconSettings style="margin-right: 8px;" />
           {{ t('system.serviceProviders.dropdown.authConfig') }}
         </a-doption>
+        <a-doption @click="handleFixedParamsWithSelect(nodeData)">
+          <IconList style="margin-right: 8px;" />
+          {{ t('system.serviceProviders.dropdown.fixedParams') }}
+        </a-doption>
         <a-doption @click="accountManageClick(nodeData)">
           <IconUser style="margin-right: 8px;" />
           {{ t('system.serviceProviders.dropdown.accountManage') }}
@@ -1719,7 +1780,22 @@
               :items="interfaceDetailTabItems"
               @change="switchInterfaceDetailTab"
             />
-            <div class="tabs-extra" v-if="selectedInterface && interfaceDetailTab !== 'detail'"></div>
+            <div v-if="selectedProvider" class="tabs-extra">
+              <a-button
+                size="small"
+                class="common-params-entry"
+                title="服务商公共参数，发布映射后对该服务商下接口生效"
+                @click="openCommonParamsFromTabs"
+              >
+                公共参数{{
+                  commonParamsLoading
+                    ? ''
+                    : commonParamsCount != null
+                      ? ` · ${commonParamsCount}`
+                      : ''
+                }}
+              </a-button>
+            </div>
           </div>
         </div>
 
@@ -1813,6 +1889,7 @@
       ref="parameterConfigFlag"
       @saved="askGoPublish"
     />
+    <FixedParameterConfig ref="fixedParameterConfigRef" @saved="onFixedParamsSaved" />
     <AccountList ref="accountList" @saved="askGoPublish" />
     <ProviderMapPublishModal ref="providerPublishRef" />
   </div>
@@ -1995,6 +2072,11 @@
         display: flex;
         align-items: center;
         flex-shrink: 0;
+        gap: 8px;
+
+        .common-params-entry {
+          color: var(--color-text-2);
+        }
       }
     }
   }