diff --git a/source/libs/transport/inc/transComm.h b/source/libs/transport/inc/transComm.h
index bc1c6386f6..c6f3066be7 100644
--- a/source/libs/transport/inc/transComm.h
+++ b/source/libs/transport/inc/transComm.h
@@ -104,6 +104,12 @@ typedef void* queue[2];
 
 #define TRANS_NOVALID_PACKET(src) ((src) != TRANS_MAGIC_NUM ? 1 : 0)
 
+#define TRANS_PACKET_LIMIT 1024 * 1024 * 512
+
+#define TRANS_MAGIC_NUM 0x5f375a86
+
+#define TRANS_NOVALID_PACKET(src) ((src) != TRANS_MAGIC_NUM ? 1 : 0)
+
 typedef SRpcMsg      STransMsg;
 typedef SRpcCtx      STransCtx;
 typedef SRpcCtxVal   STransCtxVal;
diff --git a/source/libs/transport/src/transCli.c b/source/libs/transport/src/transCli.c
index 8fdfcd5309..763483cbf6 100644
--- a/source/libs/transport/src/transCli.c
+++ b/source/libs/transport/src/transCli.c
@@ -318,10 +318,17 @@ void cliHandleResp(SCliConn* conn) {
   }
 
   STransMsgHead* pHead = NULL;
-  transDumpFromBuffer(&conn->readBuf, (char**)&pHead);
+  if (transDumpFromBuffer(&conn->readBuf, (char**)&pHead) <= 0) {
+    tDebug("%s conn %p recv invalid packet ", CONN_GET_INST_LABEL(conn), conn);
+    return;
+  }
   pHead->code = htonl(pHead->code);
   pHead->msgLen = htonl(pHead->msgLen);
 
+  if (cliRecvReleaseReq(conn, pHead)) {
+    return;
+  }
+
   STransMsg transMsg = {0};
   transMsg.contLen = transContLenFromMsg(pHead->msgLen);
   transMsg.pCont = transContFromHead((char*)pHead);
@@ -333,10 +340,6 @@ void cliHandleResp(SCliConn* conn) {
 
   SCliMsg*       pMsg = NULL;
   STransConnCtx* pCtx = NULL;
-  if (cliRecvReleaseReq(conn, pHead)) {
-    return;
-  }
-
   if (CONN_NO_PERSIST_BY_APP(conn)) {
     pMsg = transQueuePop(&conn->cliMsgs);
 
@@ -598,7 +601,12 @@ static void cliRecvCb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf) {
     pBuf->len += nread;
     while (transReadComplete(pBuf)) {
       tTrace("%s conn %p read complete", CONN_GET_INST_LABEL(conn), conn);
-      cliHandleResp(conn);
+      if (pBuf->invalid) {
+        cliHandleExcept(conn);
+        break;
+      } else {
+        cliHandleResp(conn);
+      }
     }
     return;
   }
diff --git a/source/libs/transport/src/transComm.c b/source/libs/transport/src/transComm.c
index 3ba8186e9d..a4d679b281 100644
--- a/source/libs/transport/src/transComm.c
+++ b/source/libs/transport/src/transComm.c
@@ -188,7 +188,6 @@ bool transReadComplete(SConnBuffer* connBuf) {
       p->left = 0;
     }
   }
-
   return (p->left == 0 || p->invalid) ? true : false;
 }
 
diff --git a/source/libs/transport/src/transSvr.c b/source/libs/transport/src/transSvr.c
index c980b70abd..db05aefe7b 100644
--- a/source/libs/transport/src/transSvr.c
+++ b/source/libs/transport/src/transSvr.c
@@ -198,15 +198,16 @@ static bool uvHandleReq(SSvrConn* pConn) {
   pHead->msgLen = htonl(pHead->msgLen);
   memcpy(pConn->user, pHead->user, strlen(pHead->user));
 
+  if (uvRecvReleaseReq(pConn, pHead)) {
+    return true;
+  }
+
   // TODO(dengyihao): time-consuming task throwed into BG Thread
   //  uv_work_t* wreq = taosMemoryMalloc(sizeof(uv_work_t));
   //  wreq->data = pConn;
   //  uv_read_stop((uv_stream_t*)pConn->pTcp);
   //  transRefSrvHandle(pConn);
   //  uv_queue_work(((SWorkThrd*)pConn->hostThrd)->loop, wreq, uvWorkDoTask, uvWorkAfterTask);
-  if (uvRecvReleaseReq(pConn, pHead)) {
-    return true;
-  }
 
   STransMsg transMsg;
   memset(&transMsg, 0, sizeof(transMsg));
@@ -274,14 +275,16 @@ void uvOnRecvCb(uv_stream_t* cli, ssize_t nread, const uv_buf_t* buf) {
     if (pBuf->len <= TRANS_PACKET_LIMIT) {
       while (transReadComplete(pBuf)) {
         tTrace("%s conn %p alread read complete packet", transLabel(pTransInst), conn);
-        if (uvHandleReq(conn) == false) {
+        if (pBuf->invalid) {
+          tTrace("%s conn %p alread read invalid packet", transLabel(pTransInst), conn);
           destroyConn(conn, true);
           return;
+        } else {
+          if (false == uvHandleReq(conn)) break;
         }
       }
       return;
     } else {
-      tError("%s conn %p read unexpected packet, exceed limit", transLabel(pTransInst), conn);
       destroyConn(conn, true);
       return;
     }
@@ -872,6 +875,7 @@ static int reallocConnRef(SSvrConn* conn) {
 }
 static void uvDestroyConn(uv_handle_t* handle) {
   SSvrConn* conn = handle->data;
+
   if (conn == NULL) {
     return;
   }
@@ -887,9 +891,8 @@ static void uvDestroyConn(uv_handle_t* handle) {
     SSvrMsg* msg = transQueueGet(&conn->srvMsgs, i);
     destroySmsg(msg);
   }
-
-  transReqQueueClear(&conn->wreqQueue);
   transQueueDestroy(&conn->srvMsgs);
+  transReqQueueClear(&conn->wreqQueue);
 
   QUEUE_REMOVE(&conn->queue);
   taosMemoryFree(conn->pTcp);