diff --git a/include/common/tmsg.h b/include/common/tmsg.h
index 59676fc7cb2df19c67b7a585adee9c486bbf702c..496af6d88151d3244580f7383b27076b72e4a7ee 100644
--- a/include/common/tmsg.h
+++ b/include/common/tmsg.h
@@ -679,15 +679,16 @@ int32_t tSerializeSCreateUserReq(void* buf, int32_t bufLen, SCreateUserReq* pReq
 int32_t tDeserializeSCreateUserReq(void* buf, int32_t bufLen, SCreateUserReq* pReq);
 
 typedef struct {
-  int8_t alterType;
-  int8_t superUser;
-  int8_t sysInfo;
-  int8_t enable;
-  char   user[TSDB_USER_LEN];
-  char   pass[TSDB_USET_PASSWORD_LEN];
-  char   objname[TSDB_DB_FNAME_LEN];  // db or topic
-  char   tabName[TSDB_TABLE_NAME_LEN];
-  char*  tagCond;
+  int8_t  alterType;
+  int8_t  superUser;
+  int8_t  sysInfo;
+  int8_t  enable;
+  char    user[TSDB_USER_LEN];
+  char    pass[TSDB_USET_PASSWORD_LEN];
+  char    objname[TSDB_DB_FNAME_LEN];  // db or topic
+  char    tabName[TSDB_TABLE_NAME_LEN];
+  char*   tagCond;
+  int32_t tagCondLen;
 } SAlterUserReq;
 
 int32_t tSerializeSAlterUserReq(void* buf, int32_t bufLen, SAlterUserReq* pReq);
diff --git a/source/common/src/tmsg.c b/source/common/src/tmsg.c
index f6c2aaa5a40b686ad0d0a62c7713c4bdc436c0de..a2c3919b1c1a9fc62c8c2a7c73b617f0e619af96 100644
--- a/source/common/src/tmsg.c
+++ b/source/common/src/tmsg.c
@@ -1373,11 +1373,7 @@ int32_t tSerializeSAlterUserReq(void *buf, int32_t bufLen, SAlterUserReq *pReq)
   if (len > 0) {
     if (tEncodeCStr(&encoder, pReq->tabName) < 0) return -1;
   }
-  len = (NULL == pReq->tagCond ? 0 : strlen(pReq->tagCond));
-  if (tEncodeI32(&encoder, len) < 0) return -1;
-  if (len > 0) {
-    if (tEncodeCStr(&encoder, pReq->tagCond) < 0) return -1;
-  }
+  if (tEncodeBinary(&encoder, pReq->tagCond, pReq->tagCondLen) < 0) return -1;
   tEndEncode(&encoder);
 
   int32_t tlen = encoder.pos;
@@ -1403,10 +1399,9 @@ int32_t tDeserializeSAlterUserReq(void *buf, int32_t bufLen, SAlterUserReq *pReq
     if (len > 0) {
       if (tDecodeCStrTo(&decoder, pReq->tabName) < 0) return -1;
     }
-    if (tDecodeI32(&decoder, &len) < 0) return -1;
-    if (len > 0) {
-      if (tDecodeCStrAlloc(&decoder, &pReq->tagCond) < 0) return -1;
-    }
+    uint64_t tagCondLen = 0;
+    if (tDecodeBinaryAlloc(&decoder, (void **)&pReq->tagCond, &tagCondLen) < 0) return -1;
+    pReq->tagCondLen = tagCondLen;
   }
   tEndDecode(&decoder);
 
diff --git a/source/libs/parser/src/parTranslater.c b/source/libs/parser/src/parTranslater.c
index 1c88899dcf0b300255985e233f58a8ea97d6aa25..06bd666609268686859968b60b5d09c136f91701 100644
--- a/source/libs/parser/src/parTranslater.c
+++ b/source/libs/parser/src/parTranslater.c
@@ -6467,7 +6467,7 @@ static int32_t translateGrant(STranslateContext* pCxt, SGrantStmt* pStmt) {
   sprintf(req.tabName, "%s", pStmt->tabName);
   int32_t code = TSDB_CODE_SUCCESS;
   if (NULL != pStmt->pTagCond) {
-    code = nodesNodeToString(pStmt->pTagCond, false, &req.tagCond, NULL);
+    code = nodesNodeToString(pStmt->pTagCond, false, &req.tagCond, &req.tagCondLen);
   }
   if (TSDB_CODE_SUCCESS == code) {
     code = buildCmdMsg(pCxt, TDMT_MND_ALTER_USER, (FSerializeFunc)tSerializeSAlterUserReq, &req);