diff --git a/src/Oms.Application/Shared/PriceAreaSnapshotHelper.cs b/src/Oms.Application/Shared/PriceAreaSnapshotHelper.cs
index d06e44f..ab0bd80 100644
--- a/src/Oms.Application/Shared/PriceAreaSnapshotHelper.cs
+++ b/src/Oms.Application/Shared/PriceAreaSnapshotHelper.cs
@@ -1,5 +1,6 @@
 using Oms.Application.Dtos.Channels;
 using Oms.Application.Dtos.Orders;
+using Oms.Application.Services.Orders;
 using Oms.Domain.ChannelsAggregate.Entities;
 using Oms.Domain.ChannelsAggregate.Repositories;
 
@@ -11,7 +12,7 @@ namespace Oms.Application.Shared;
 public static class PriceAreaSnapshotHelper
 {
     /// <summary>
-    /// 按产品 PriceAreaId 加载分区头与明细写入快照。
+    /// 按产品 PriceAreaId（或从卖价明细分区推断）加载分区头与明细写入快照。
     /// </summary>
     public static async Task ApplyPriceAreaToSnapshotAsync(
         SalesProductPricePublishSnapshotDto snapshot,
@@ -19,7 +20,12 @@ public static class PriceAreaSnapshotHelper
         IKpiAreaRepository kpiAreaRepository,
         CancellationToken cancellationToken = default)
     {
-        if (!product.PriceAreaId.HasValue || product.PriceAreaId <= 0)
+        var priceAreaId = await ResolvePriceAreaIdAsync(
+            product,
+            snapshot,
+            kpiAreaRepository,
+            cancellationToken);
+        if (!priceAreaId.HasValue)
         {
             snapshot.PriceAreaId = null;
             snapshot.PriceAreaName = null;
@@ -27,13 +33,48 @@ public static class PriceAreaSnapshotHelper
             return;
         }
 
-        snapshot.PriceAreaId = product.PriceAreaId;
-        var area = await kpiAreaRepository.FirstOrDefaultAsync(x => x.Id == product.PriceAreaId.Value, cancellationToken);
+        snapshot.PriceAreaId = priceAreaId;
+        var area = await kpiAreaRepository.FirstOrDefaultAsync(x => x.Id == priceAreaId.Value, cancellationToken);
         snapshot.PriceAreaName = area?.Name;
-        var infos = await kpiAreaRepository.GetAllInfosByAreaIdAsync(product.PriceAreaId.Value, cancellationToken);
+        var infos = await kpiAreaRepository.GetAllInfosByAreaIdAsync(priceAreaId.Value, cancellationToken);
         snapshot.PriceAreaInfos = infos.Select(MapInfoOutput).ToList();
     }
 
+    internal static async Task<int?> ResolvePriceAreaIdAsync(
+        SalesProduct product,
+        SalesProductPricePublishSnapshotDto snapshot,
+        IKpiAreaRepository kpiAreaRepository,
+        CancellationToken cancellationToken = default)
+    {
+        if (product.PriceAreaId is > 0)
+        {
+            return product.PriceAreaId;
+        }
+
+        var zoneKeys = ParcelBillingCalculator.CollectDistinctDetailZoneKeys(snapshot);
+        foreach (var zoneKey in zoneKeys)
+        {
+            if (!int.TryParse(zoneKey.Trim(), out var zoneId) || zoneId <= 0)
+            {
+                continue;
+            }
+
+            var area = await kpiAreaRepository.FirstOrDefaultAsync(x => x.Id == zoneId, cancellationToken);
+            if (area != null)
+            {
+                return zoneId;
+            }
+
+            var info = await kpiAreaRepository.GetInfoByIdAsync(zoneId, cancellationToken);
+            if (info != null)
+            {
+                return info.AreaId;
+            }
+        }
+
+        return null;
+    }
+
     private static KpiAreaInfoOutput MapInfoOutput(KpiAreaInfo entity) =>
         new()
         {