diff --git a/src/Api/TakeoutSaaS.TenantApi/Services/ProductSkuSaveService.cs b/src/Api/TakeoutSaaS.TenantApi/Services/ProductSkuSaveService.cs
index a5dc240..75fb21c 100644
--- a/src/Api/TakeoutSaaS.TenantApi/Services/ProductSkuSaveService.cs
+++ b/src/Api/TakeoutSaaS.TenantApi/Services/ProductSkuSaveService.cs
@@ -89,6 +89,7 @@ public sealed class ProductSkuSaveService(TakeoutAppDbContext dbContext)
             .ToDictionary(group => group.Key, group => new Queue<ProductSku>(group), StringComparer.Ordinal);
 
         var usedExistingSkuIds = new HashSet<long>();
+        var plannedSkuCodes = new HashSet<string>(StringComparer.Ordinal);
         var currentProductSkuCodes = existingSkus
             .Where(item => !string.IsNullOrWhiteSpace(item.SkuCode))
             .Select(item => item.SkuCode)
@@ -119,6 +120,20 @@ public sealed class ProductSkuSaveService(TakeoutAppDbContext dbContext)
             if (matched is not null)
             {
                 usedExistingSkuIds.Add(matched.Id);
+                var targetSkuCode = !string.IsNullOrWhiteSpace(normalizedSkuCode)
+                    ? normalizedSkuCode
+                    : NormalizeSkuCode(matched.SkuCode);
+                if (string.IsNullOrWhiteSpace(targetSkuCode))
+                {
+                    targetSkuCode = GenerateUniqueSkuCode(productId, currentProductSkuCodes);
+                }
+
+                if (!plannedSkuCodes.Add(targetSkuCode))
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, $"SKU 编码冲突: {targetSkuCode}");
+                }
+
+                currentProductSkuCodes.Add(targetSkuCode);
                 matched.Price = sku.Price;
                 matched.OriginalPrice = sku.OriginalPrice;
                 matched.StockQuantity = Math.Max(0, sku.Stock);
@@ -127,15 +142,17 @@ public sealed class ProductSkuSaveService(TakeoutAppDbContext dbContext)
                 matched.IsEnabled = sku.IsEnabled;
                 matched.DeletedAt = null;
                 matched.DeletedBy = null;
-                if (!string.IsNullOrWhiteSpace(normalizedSkuCode))
-                {
-                    matched.SkuCode = normalizedSkuCode;
-                }
+                matched.SkuCode = targetSkuCode;
 
                 continue;
             }
 
             var generatedCode = normalizedSkuCode ?? GenerateUniqueSkuCode(productId, currentProductSkuCodes);
+            if (!plannedSkuCodes.Add(generatedCode))
+            {
+                throw new BusinessException(ErrorCodes.BadRequest, $"SKU 编码冲突: {generatedCode}");
+            }
+
             currentProductSkuCodes.Add(generatedCode);
             createdSkus.Add(new ProductSku
             {
@@ -157,6 +174,11 @@ public sealed class ProductSkuSaveService(TakeoutAppDbContext dbContext)
                 continue;
             }
 
+            if (!string.IsNullOrWhiteSpace(existing.SkuCode) && plannedSkuCodes.Contains(existing.SkuCode))
+            {
+                throw new BusinessException(ErrorCodes.BadRequest, $"SKU 编码已存在: {existing.SkuCode}");
+            }
+
             existing.IsEnabled = false;
             existing.StockQuantity = 0;
         }