diff --git a/src/Oms.Application/Storage/FileStoragePath.cs b/src/Oms.Application/Storage/FileStoragePath.cs
index a9af070..6a17bbe 100644
--- a/src/Oms.Application/Storage/FileStoragePath.cs
+++ b/src/Oms.Application/Storage/FileStoragePath.cs
@@ -28,7 +28,32 @@ public static class FileStoragePath
             throw new ArgumentException("object key 不能为空", nameof(pathOrUrl));
         }
 
-        return key;
+        // 自定义域公开 URL 常带 PathBase「admin/」；库内/COS 逻辑 key 为 uploads/...。
+        // 若不剥离，GetUrl 再拼 KeyPrefix/PathBase 会变成 admin/admin/uploads → NoSuchKey。
+        return StripPublicPathBase(key);
+    }
+
+    /// <summary>
+    /// 去掉公开 URL 上的 PathBase（可重复的 admin/），保留 uploads/... 等逻辑 key。
+    /// </summary>
+    public static string StripPublicPathBase(string key)
+    {
+        var value = key.Replace('\\', '/').Trim().TrimStart('/');
+        while (value.StartsWith("admin/", StringComparison.OrdinalIgnoreCase))
+        {
+            var rest = value["admin/".Length..];
+            // 仅剥「PathBase + 业务前缀」；避免误伤 admin 业务目录（若有）
+            if (rest.StartsWith("uploads/", StringComparison.OrdinalIgnoreCase)
+                || rest.StartsWith("admin/", StringComparison.OrdinalIgnoreCase))
+            {
+                value = rest;
+                continue;
+            }
+
+            break;
+        }
+
+        return value;
     }
 
     /// <summary>
diff --git a/src/Oms.Tests/FileStoragePathTests.cs b/src/Oms.Tests/FileStoragePathTests.cs
index 9a26ce1..493c7d9 100644
--- a/src/Oms.Tests/FileStoragePathTests.cs
+++ b/src/Oms.Tests/FileStoragePathTests.cs
@@ -15,8 +15,9 @@ public class FileStoragePathTests
 
         var keys = FileStoragePath.ExpandReadKeys(url);
 
-        keys.Should().Contain("admin/uploads/prints/orders/IDE2610061059117673-20261006105912.pdf");
+        // NormalizeKey 已剥 PathBase，主 key 为 uploads/...；Expand 仍保留 admin/ 候选以兼容历史对象
         keys.Should().Contain("uploads/prints/orders/IDE2610061059117673-20261006105912.pdf");
+        keys.Should().Contain("admin/uploads/prints/orders/IDE2610061059117673-20261006105912.pdf");
     }
 
     [Theory]
@@ -41,6 +42,47 @@ public class FileStoragePathTests
             .Be("uploads/prints/orders/IDE2610081704036507-20261008170404.pdf");
     }
 
+    [Fact]
+    public void ToStorageKey_ShouldStripPathBaseAdminFromCustomDomainUrl()
+    {
+        var url =
+            "https://cos.test.ideship.com/admin/uploads/prints/orders/IDE2610231052073356-20261023105208.pdf?q-sign-algorithm=sha1";
+
+        OmsObjectStorageExtensions.ToStorageKey(url)
+            .Should()
+            .Be("uploads/prints/orders/IDE2610231052073356-20261023105208.pdf");
+    }
+
+    [Fact]
+    public void NormalizeKey_ShouldCollapseDoubleAdminPathBase()
+    {
+        FileStoragePath.NormalizeKey("admin/admin/uploads/prints/orders/a.pdf")
+            .Should()
+            .Be("uploads/prints/orders/a.pdf");
+    }
+
+    [Fact]
+    public async Task GetPublicUrl_ShouldResignCustomDomainUrlWithoutDoubleAdmin()
+    {
+        var expired =
+            "https://cos.test.ideship.com/admin/uploads/prints/orders/IDE2610231052073356-20261023105208.pdf?q-sign-algorithm=sha1&q-sign-time=1;2";
+        const string fresh =
+            "https://cos.test.ideship.com/admin/uploads/prints/orders/IDE2610231052073356-20261023105208.pdf?q-sign-algorithm=sha1&fresh=1";
+
+        var storage = new Mock<IObjectStorage>(MockBehavior.Strict);
+        storage
+            .Setup(x => x.GetUrlAsync(
+                "uploads/prints/orders/IDE2610231052073356-20261023105208.pdf",
+                It.IsAny<TimeSpan?>(),
+                It.IsAny<CancellationToken>()))
+            .ReturnsAsync(fresh);
+
+        var url = await storage.Object.GetPublicUrlAsync(expired);
+
+        url.Should().Be(fresh);
+        storage.VerifyAll();
+    }
+
     [Fact]
     public void ToStorageKey_ShouldKeepExternalAbsoluteUrl()
     {