diff --git a/Lagrange.Core/Internal/Service/Message/MultiMsgUploadService.cs b/Lagrange.Core/Internal/Service/Message/MultiMsgUploadService.cs
index 1be619593..207af4c07 100644
--- a/Lagrange.Core/Internal/Service/Message/MultiMsgUploadService.cs
+++ b/Lagrange.Core/Internal/Service/Message/MultiMsgUploadService.cs
@@ -18,8 +18,7 @@ protected override bool Build(MultiMsgUploadEvent input, BotKeystore keystore, B
     {
         if (input.Chains == null) throw new ArgumentNullException(nameof(input.Chains));
         
-        var msgPacker = new MessagePacker(keystore.Uid ?? "");
-        var msgBody = input.Chains.Select(msgPacker.BuildFake).ToList();
+        var msgBody = input.Chains.Select(x => MessagePacker.BuildFake(x, keystore.Uid ?? "")).ToList();
         var longMsgResult = new LongMsgResult
         {
             Action = new LongMsgAction
diff --git a/Lagrange.Core/Internal/Service/Message/SendMessageService.cs b/Lagrange.Core/Internal/Service/Message/SendMessageService.cs
index 9c0ca0a06..6e74529d0 100644
--- a/Lagrange.Core/Internal/Service/Message/SendMessageService.cs
+++ b/Lagrange.Core/Internal/Service/Message/SendMessageService.cs
@@ -15,8 +15,7 @@ internal class SendMessageService : BaseService<SendMessageEvent>
     protected override bool Build(SendMessageEvent input, BotKeystore keystore, BotAppInfo appInfo, BotDeviceInfo device,
         out BinaryPacket output, out List<BinaryPacket>? extraPackets)
     {
-        var packer = new MessagePacker(keystore.Uid ?? throw new Exception("No UID found in keystore"));
-        var packet = packer.Build(input.Chain);
+        var packet = MessagePacker.Build(input.Chain, keystore.Uid ?? throw new Exception("No UID found in keystore"));
 
         using var stream = new MemoryStream();
         Serializer.Serialize(stream, packet);
diff --git a/Lagrange.Core/Message/MessagePacker.cs b/Lagrange.Core/Message/MessagePacker.cs
index cd80aa6ab..19d78dc71 100644
--- a/Lagrange.Core/Message/MessagePacker.cs
+++ b/Lagrange.Core/Message/MessagePacker.cs
@@ -19,14 +19,12 @@ namespace Lagrange.Core.Message;
 /// <summary>
 /// Pack up message into the Protobuf <see cref="Message"/>
 /// </summary>
-internal class MessagePacker
+internal static class MessagePacker
 {
     private static readonly Dictionary<Type, List<PropertyInfo>> EntityToElem;
     private static readonly Dictionary<Type, IMessageEntity> Factory;
     private static readonly List<IMessageEntity> MsgFactory;
-
-    private readonly string _selfUid;
-
+    
     static MessagePacker()
     {
         EntityToElem = new Dictionary<Type, List<PropertyInfo>>();
@@ -56,19 +54,14 @@ static MessagePacker()
 
         MsgFactory = assembly.GetImplementations<IMessageEntity>().Select(type => (IMessageEntity)type.CreateInstance()).ToList();
     }
-    
-    public MessagePacker(string selfUid)
-    {
-        _selfUid = selfUid;
-    }
 
-    public Internal.Packets.Message.Message Build(MessageChain chain)
+    public static Internal.Packets.Message.Message Build(MessageChain chain, string selfUid)
     {
         var message = BuildPacketBase(chain);
 
         foreach (var entity in chain)
         {
-            entity.SetSelfUid(_selfUid);
+            entity.SetSelfUid(selfUid);
             
             if (message.Body != null)
             {
@@ -86,13 +79,13 @@ public Internal.Packets.Message.Message Build(MessageChain chain)
         return message;
     }
     
-    public PushMsgBody BuildFake(MessageChain chain)
+    public static PushMsgBody BuildFake(MessageChain chain, string selfUid)
     {
         var message = BuildFakePacketBase(chain);
 
         foreach (var entity in chain)
         {
-            entity.SetSelfUid(_selfUid);
+            entity.SetSelfUid(selfUid);
             
             if (message.Body != null)
             {