diff --git a/src/JT809.Protocol/Internal/JT809BusinessTypeFactory.cs b/src/JT809.Protocol/Internal/JT809BusinessTypeFactory.cs
index be74f03..659ef1c 100644
--- a/src/JT809.Protocol/Internal/JT809BusinessTypeFactory.cs
+++ b/src/JT809.Protocol/Internal/JT809BusinessTypeFactory.cs
@@ -33,10 +33,12 @@ namespace JT808.Protocol.Internal
                 var instance = Activator.CreateInstance(type);
                 ushort msgId = 0;
                 JT809Version version;
+                bool replaceInternalMsgId;
                 try
                 {
                     msgId = (ushort)type.GetProperty(nameof(JT809Bodies.MsgId)).GetValue(instance);
                     version = (JT809Version)type.GetProperty(nameof(JT809Bodies.Version)).GetValue(instance);
+                    replaceInternalMsgId = (bool)type.GetProperty(nameof(JT809Bodies.ReplaceInternalMsgId)).GetValue(instance);
                 }
                 catch (Exception ex)
                 {
@@ -44,13 +46,20 @@ namespace JT808.Protocol.Internal
                 }
                 if (Map_2019.ContainsKey(msgId))
                 {
-                    if (version == JT809Version.JTT2019)
+                    if (replaceInternalMsgId)
                     {
                         Map_2019[msgId] = instance;
                     }
                     else
                     {
-                        throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                        if (version == JT809Version.JTT2019)
+                        {
+                            Map_2019[msgId] = instance;
+                        }
+                        else
+                        {
+                            throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                        }
                     }
                 }
                 else
@@ -61,7 +70,14 @@ namespace JT808.Protocol.Internal
                 {
                     if (version != JT809Version.JTT2019)
                     {
-                        throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                        if (replaceInternalMsgId)
+                        {
+                            Map[msgId] = instance;
+                        }
+                        else
+                        {
+                            throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                        }
                     }   
                 }
                 else
@@ -77,11 +93,19 @@ namespace JT808.Protocol.Internal
             var instance = Activator.CreateInstance(type);
             var msgId = (ushort)type.GetProperty(nameof(JT809Bodies.MsgId)).GetValue(instance);
             JT809Version version = (JT809Version)type.GetProperty(nameof(JT809Bodies.Version)).GetValue(instance);
+            bool replaceInternalMsgId = (bool)type.GetProperty(nameof(JT809Bodies.ReplaceInternalMsgId)).GetValue(instance);
             if (Map.ContainsKey(msgId))
             {
-                if (version != JT809Version.JTT2019)
+                if (replaceInternalMsgId)
                 {
-                    throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                    Map[msgId] = instance;
+                }
+                else
+                {
+                    if (version != JT809Version.JTT2019)
+                    {
+                        throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                    }
                 }
             }
             else
@@ -90,13 +114,20 @@ namespace JT808.Protocol.Internal
             }
             if (Map_2019.ContainsKey(msgId))
             {
-                if (version == JT809Version.JTT2019)
+                if (replaceInternalMsgId)
                 {
                     Map_2019[msgId] = instance;
                 }
                 else
                 {
-                    throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                    if (version == JT809Version.JTT2019)
+                    {
+                        Map_2019[msgId] = instance;
+                    }
+                    else
+                    {
+                        throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                    }
                 }
             }
             else
diff --git a/src/JT809.Protocol/Internal/JT809SubBusinessTypeFactory.cs b/src/JT809.Protocol/Internal/JT809SubBusinessTypeFactory.cs
index 07feac2..ea94eae 100644
--- a/src/JT809.Protocol/Internal/JT809SubBusinessTypeFactory.cs
+++ b/src/JT809.Protocol/Internal/JT809SubBusinessTypeFactory.cs
@@ -27,9 +27,11 @@ namespace JT808.Protocol.Internal
             {
                 var instance = Activator.CreateInstance(type);
                 ushort msgId = 0;
+                bool replaceInternalSubMsgId;
                 try
                 {
                     msgId = (ushort)type.GetProperty(nameof(JT809SubBodies.SubMsgId)).GetValue(instance);
+                    replaceInternalSubMsgId = (bool)type.GetProperty(nameof(JT809SubBodies.ReplaceInternalSubMsgId)).GetValue(instance);
                 }
                 catch (Exception ex)
                 {
@@ -37,7 +39,14 @@ namespace JT808.Protocol.Internal
                 }
                 if (Map.ContainsKey(msgId))
                 {
-                    throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                    if (replaceInternalSubMsgId)
+                    {
+                        Map[msgId] = instance;
+                    }
+                    else
+                    {
+                        throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                    }
                 }
                 else
                 {
@@ -56,9 +65,17 @@ namespace JT808.Protocol.Internal
             Type type = typeof(TJT809SubBodies);
             var instance = Activator.CreateInstance(type);
             var msgId = (ushort)type.GetProperty(nameof(JT809SubBodies.SubMsgId)).GetValue(instance);
+            bool replaceInternalSubMsgId = (bool)type.GetProperty(nameof(JT809SubBodies.ReplaceInternalSubMsgId)).GetValue(instance);
             if (Map.ContainsKey(msgId))
             {
-                throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                if (replaceInternalSubMsgId)
+                {
+                    Map[msgId] = instance;
+                }
+                else
+                {
+                    throw new ArgumentException($"{type.FullName} {msgId} An element with the same key already exists.");
+                }
             }
             else
             {
diff --git a/src/JT809.Protocol/JT809.Protocol.csproj b/src/JT809.Protocol/JT809.Protocol.csproj
index 494b645..80f6975 100644
--- a/src/JT809.Protocol/JT809.Protocol.csproj
+++ b/src/JT809.Protocol/JT809.Protocol.csproj
@@ -14,7 +14,7 @@
     <PackageProjectUrl>https://github.com/SmallChi/JT809</PackageProjectUrl>
     <license>https://github.com/SmallChi/JT809/blob/master/LICENSE</license>
     <GeneratePackageOnBuild>false</GeneratePackageOnBuild>
-    <Version>2.1.4-preview2</Version>
+    <Version>2.1.4-preview3</Version>
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
   </PropertyGroup>
 
diff --git a/src/JT809.Protocol/JT809Bodies.cs b/src/JT809.Protocol/JT809Bodies.cs
index 1255764..7c8f5f2 100644
--- a/src/JT809.Protocol/JT809Bodies.cs
+++ b/src/JT809.Protocol/JT809Bodies.cs
@@ -15,5 +15,10 @@ namespace JT809.Protocol
         public abstract ushort MsgId { get; }
         public abstract JT809_LinkType LinkType { get; }
         public abstract string Description { get; }
+        /// <summary>
+        /// 当外部注册的扩展809的消息Id跟国标的消息Id冲突时可以使用该字段替换国标的消息Id
+        /// 默认是false,不替换
+        /// </summary>
+        public virtual bool ReplaceInternalMsgId { get; } = false;
     }
 }
diff --git a/src/JT809.Protocol/JT809SubBodies.cs b/src/JT809.Protocol/JT809SubBodies.cs
index 543593e..6b284b8 100644
--- a/src/JT809.Protocol/JT809SubBodies.cs
+++ b/src/JT809.Protocol/JT809SubBodies.cs
@@ -17,5 +17,10 @@ namespace JT809.Protocol
         public abstract ushort SubMsgId { get; }
 
         public abstract string Description { get; }
+        /// <summary>
+        /// 当外部注册的扩展809的消息Id跟国标的消息Id冲突时可以使用该字段替换国标的消息Id
+        /// 默认是false,不替换
+        /// </summary>
+        public virtual bool ReplaceInternalSubMsgId { get; } = false;
     }
 }