diff --git a/src/inc/tsdb.h b/src/inc/tsdb.h
index 79d9029dbc..7575951246 100644
--- a/src/inc/tsdb.h
+++ b/src/inc/tsdb.h
@@ -117,7 +117,7 @@ typedef struct {
 
 void tsdbClearTableCfg(STableCfg *config);
 
-void *tsdbGetTableTagVal(const void *pTable, int32_t colId, int16_t type, int16_t bytes);
+void *tsdbGetTableTagVal(const void *pTable, int32_t colId, int16_t type, int16_t* bytes);
 char *tsdbGetTableName(void *pTable);
 
 #define TSDB_TABLEID(_table) ((STableId*) (_table))
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 77ceabbd63..4a5dc4f506 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -2819,7 +2819,7 @@ static void doSetTagValueInParam(void* pTable, int32_t tagColId, tVariant *tag,
     val = tsdbGetTableName(pTable);
     assert(val != NULL);
   } else {
-    val = tsdbGetTableTagVal(pTable, tagColId, type, bytes);
+    val = tsdbGetTableTagVal(pTable, tagColId, type, &bytes);
   }
 
   if (val == NULL || isNull(val, type)) {
@@ -6011,7 +6011,7 @@ static SSDataBlock* doTagScan(void* param, bool* newgroup) {
       if (pExprInfo->base.colInfo.colId == TSDB_TBNAME_COLUMN_INDEX) {
         data = tsdbGetTableName(item->pTable);
       } else {
-        data = tsdbGetTableTagVal(item->pTable, pExprInfo->base.colInfo.colId, type, bytes);
+        data = tsdbGetTableTagVal(item->pTable, pExprInfo->base.colInfo.colId, type, &bytes);
       }
 
       doSetTagValueToResultBuf(output, data, type, bytes);
@@ -6050,7 +6050,7 @@ static SSDataBlock* doTagScan(void* param, bool* newgroup) {
         if (pExprInfo[j].base.colInfo.colId == TSDB_TBNAME_COLUMN_INDEX) {
           data = tsdbGetTableName(item->pTable);
         } else {
-          data = tsdbGetTableTagVal(item->pTable, pExprInfo[j].base.colInfo.colId, type, bytes);
+          data = tsdbGetTableTagVal(item->pTable, pExprInfo[j].base.colInfo.colId, type, &bytes);
         }
 
         dst  = pColInfo->pData + count * pExprInfo[j].base.resBytes;
diff --git a/src/tsdb/src/tsdbMeta.c b/src/tsdb/src/tsdbMeta.c
index 8174698197..52ba3dfb4e 100644
--- a/src/tsdb/src/tsdbMeta.c
+++ b/src/tsdb/src/tsdbMeta.c
@@ -201,7 +201,7 @@ _err:
   return -1;
 }
 
-void *tsdbGetTableTagVal(const void* pTable, int32_t colId, int16_t type, int16_t bytes) {
+void *tsdbGetTableTagVal(const void* pTable, int32_t colId, int16_t type, int16_t* bytes) {
   // TODO: this function should be changed also
 
   STSchema *pSchema = tsdbGetTableTagSchema((STable*) pTable);
@@ -211,8 +211,16 @@ void *tsdbGetTableTagVal(const void* pTable, int32_t colId, int16_t type, int16_
   }
 
   char *val = tdGetKVRowValOfCol(((STable*)pTable)->tagVal, colId);
-  assert(type == pCol->type && bytes == pCol->bytes);
+  assert(type == pCol->type &&
+         // if var data type,bytes may >= col bytes,in case of tag width has beed modified
+        ((IS_VAR_DATA_TYPE(type) && *bytes >= pCol->bytes) ||
+        // otherwise, bytes must be equal to colomn bytes
+        (!IS_VAR_DATA_TYPE(type) && *bytes == pCol->bytes)));
 
+  // in case tag width has been modified bigger but vnode has not been notified
+  if (val != NULL && IS_VAR_DATA_TYPE(type) && *bytes > pCol->bytes) {
+    *bytes = pCol->bytes;
+  }
   // if (val != NULL && IS_VAR_DATA_TYPE(type)) {
   //   assert(varDataLen(val) < pCol->bytes);
   // }