diff --git a/AssetManager.Infrastructure/Services/MarketDataService.cs b/AssetManager.Infrastructure/Services/MarketDataService.cs
index 7e03aa2..c84b5a0 100755
--- a/AssetManager.Infrastructure/Services/MarketDataService.cs
+++ b/AssetManager.Infrastructure/Services/MarketDataService.cs
@@ -27,6 +27,9 @@ public class MarketDataService : IMarketDataService
     
     // 静态 pending 请求字典（跨请求共享，防止并发请求同一股票）
     private static readonly ConcurrentDictionary<string, Lazy<Task<MarketPriceResponse>>> _pendingPriceRequests = new();
+    
+    // 静态写入锁（串行化数据库写入）
+    private static readonly SemaphoreSlim _writeLock = new(1, 1);
 
     public MarketDataService(
         ILogger<MarketDataService> logger,
@@ -200,9 +203,10 @@ public class MarketDataService : IMarketDataService
             ExpiredAt = expireAt
         }, expireAt);
         
-        // 写入数据库缓存（Fire-and-Forget，失败不影响主流程）
+        // 写入数据库缓存（串行化，避免连接冲突）
         _ = Task.Run(async () =>
         {
+            await _writeLock.WaitAsync();
             try
             {
                 await SavePriceCacheAsync(symbol, assetType, response, source);
@@ -211,6 +215,10 @@ public class MarketDataService : IMarketDataService
             {
                 _logger.LogWarning(ex, "[数据库缓存写入失败] Symbol={Symbol}，忽略（内存缓存已生效）", symbol);
             }
+            finally
+            {
+                _writeLock.Release();
+            }
         });
         
         return response;