diff --git a/Lagrange.Core/Internal/Events/System/FileUploadEvent.cs b/Lagrange.Core/Internal/Events/System/FileUploadEvent.cs
index 86aa7814..19ce9b37 100644
--- a/Lagrange.Core/Internal/Events/System/FileUploadEvent.cs
+++ b/Lagrange.Core/Internal/Events/System/FileUploadEvent.cs
@@ -2,7 +2,7 @@
 
 namespace Lagrange.Core.Internal.Events.System;
 
-internal class FileUploadEventReq(string targetUid, Stream fileStream, string fileName) : ProtocolEvent
+internal class FileUploadEventReq(string targetUid, Stream fileStream, string fileName, byte[] md510m) : ProtocolEvent
 {
     public string TargetUid { get; } = targetUid;
 
@@ -12,6 +12,8 @@ internal class FileUploadEventReq(string targetUid, Stream fileStream, string fi
 
     public byte[] FileMd5 { get; } = fileStream.Md5();
     
+    public byte[] File10MMd5 { get; } = md510m;
+    
     public byte[] FileSha1 { get; } = fileStream.Sha1();
 }
 
diff --git a/Lagrange.Core/Internal/Logic/OperationLogic.cs b/Lagrange.Core/Internal/Logic/OperationLogic.cs
index bf86f1e5..e357f24e 100644
--- a/Lagrange.Core/Internal/Logic/OperationLogic.cs
+++ b/Lagrange.Core/Internal/Logic/OperationLogic.cs
@@ -88,15 +88,17 @@ public async Task<string> GroupFSDownload(long groupUin, string fileId)
         fileName = ResolveFileName(fileStream, fileName);
 
         var friend = await context.CacheContext.ResolveFriend(targetUin) ?? throw new InvalidTargetException(targetUin);
-        var request = new FileUploadEventReq(friend.Uid, fileStream, fileName);
-        var result = await context.EventContext.SendEvent<FileUploadEventResp>(request);
-
-        var buffer = ArrayPool<byte>.Shared.Rent(10 * 1024 * 1024);
-        int payload = await fileStream.ReadAsync(buffer.AsMemory(0, 10 * 1024 * 1024));
+        
+        var buffer = ArrayPool<byte>.Shared.Rent(10002432);
+        int payload = await fileStream.ReadAsync(buffer.AsMemory(0, 10002432));
         var md510m = MD5.HashData(buffer[..payload]);
         ArrayPool<byte>.Shared.Return(buffer);
-        request.FileStream.Seek(0, SeekOrigin.Begin);
+        fileStream.Seek(0, SeekOrigin.Begin);
+        
+        var request = new FileUploadEventReq(friend.Uid, fileStream, fileName, md510m);
+        var result = await context.EventContext.SendEvent<FileUploadEventResp>(request);
 
+        
         if (!result.IsExist)
         {
             var ext = new FileUploadExt
@@ -176,8 +178,8 @@ public async Task<string> SendGroupFile(long groupUin, Stream fileStream, string
         var request = new GroupFSUploadEventReq(groupUin, fileName, fileStream, parentDirectory, md5);
         var uploadResp = await context.EventContext.SendEvent<GroupFSUploadEventResp>(request);
 
-        var buffer = ArrayPool<byte>.Shared.Rent(10 * 1024 * 1024);
-        int payload = await fileStream.ReadAsync(buffer.AsMemory(0, 10 * 1024 * 1024));
+        var buffer = ArrayPool<byte>.Shared.Rent(10002432);
+        int payload = await fileStream.ReadAsync(buffer.AsMemory(0, 10002432));
         var md510m = MD5.HashData(buffer[..payload]);
         ArrayPool<byte>.Shared.Return(buffer);
         fileStream.Seek(0, SeekOrigin.Begin);
diff --git a/Lagrange.Core/Internal/Services/System/FileUploadService.cs b/Lagrange.Core/Internal/Services/System/FileUploadService.cs
index 534346b8..abfff9ad 100644
--- a/Lagrange.Core/Internal/Services/System/FileUploadService.cs
+++ b/Lagrange.Core/Internal/Services/System/FileUploadService.cs
@@ -19,12 +19,6 @@ internal class FileUploadService : OidbService<FileUploadEventReq, FileUploadEve
     
     private protected override Task<OfflineFileUploadRequest> ProcessRequest(FileUploadEventReq request, BotContext context)
     {
-        var buffer = ArrayPool<byte>.Shared.Rent(10 * 1024 * 1024);
-        int payload = request.FileStream.Read(buffer);
-        var md510m = MD5.HashData(buffer[..payload]);
-        ArrayPool<byte>.Shared.Return(buffer);
-        request.FileStream.Seek(0, SeekOrigin.Begin);
-        
         return Task.FromResult(new OfflineFileUploadRequest
         {
             Command = 1700,
@@ -35,7 +29,7 @@ private protected override Task<OfflineFileUploadRequest> ProcessRequest(FileUpl
                 ReceiverUid = request.TargetUid,
                 FileSize = (uint)request.FileStream.Length,
                 FileName = request.FileName,
-                Md510MCheckSum = md510m,
+                Md510MCheckSum = request.File10MMd5,
                 Sha1CheckSum = request.FileSha1,
                 LocalPath = "/",
                 Md5CheckSum = request.FileMd5,
diff --git a/Lagrange.Core/Message/MessagePacker.cs b/Lagrange.Core/Message/MessagePacker.cs
index dc3a3691..0e53d0af 100644
--- a/Lagrange.Core/Message/MessagePacker.cs
+++ b/Lagrange.Core/Message/MessagePacker.cs
@@ -180,7 +180,7 @@ public static ReadOnlyMemory<byte> BuildTrans0X211(BotFriend friend, FileUploadE
             {
                 FileType = 0,
                 FileUuid = resp.FileId,
-                FileMd5 = req.FileMd5,
+                FileMd5 = req.File10MMd5,
                 FileName = req.FileName,
                 FileSize = (ulong)req.FileStream.Length,
                 SubCmd = 1,