diff --git a/source/client/src/clientRawBlockWrite.c b/source/client/src/clientRawBlockWrite.c
index 6331224c3a..3a23d38375 100644
--- a/source/client/src/clientRawBlockWrite.c
+++ b/source/client/src/clientRawBlockWrite.c
@@ -755,9 +755,9 @@ static void processAlterTable(SMqMetaRsp* metaRsp, cJSON** pJson) {
         }
 
         cJSON* colValue = cJSON_CreateString(buf);
+        taosMemoryFree(buf);
         RAW_NULL_CHECK(colValue);
         RAW_FALSE_CHECK(cJSON_AddItemToObject(json, "colValue", colValue));
-        taosMemoryFree(buf);
       }
 
       cJSON* isNullCJson = cJSON_CreateBool(isNull);
@@ -804,9 +804,9 @@ static void processAlterTable(SMqMetaRsp* metaRsp, cJSON** pJson) {
             goto end;
           }
           cJSON* colValue = cJSON_CreateString(buf);
+          taosMemoryFree(buf);
           RAW_NULL_CHECK(colValue);
           RAW_FALSE_CHECK(cJSON_AddItemToObject(member, "colValue", colValue));
-          taosMemoryFree(buf);
         }
         cJSON* isNullCJson = cJSON_CreateBool(isNull);
         RAW_NULL_CHECK(isNullCJson);
diff --git a/source/dnode/vnode/src/meta/metaTable.c b/source/dnode/vnode/src/meta/metaTable.c
index 8256b5e402..65e520bb4a 100644
--- a/source/dnode/vnode/src/meta/metaTable.c
+++ b/source/dnode/vnode/src/meta/metaTable.c
@@ -2215,11 +2215,6 @@ static int metaUpdateTableMultiTagVal(SMeta *pMeta, int64_t version, SVAlterTbRe
     metaError("meta/table: failed to update tag idx:%s uid:%" PRId64, ctbEntry.name, ctbEntry.uid);
   }
 
-  if (NULL == ctbEntry.ctbEntry.pTags) {
-    metaError("meta/table: null tags, update tag val failed.");
-    goto _err;
-  }
-
   SCtbIdxKey ctbIdxKey = {.suid = ctbEntry.ctbEntry.suid, .uid = uid};
   if (tdbTbUpsert(pMeta->pCtbIdx, &ctbIdxKey, sizeof(ctbIdxKey), ctbEntry.ctbEntry.pTags,
                   ((STag *)(ctbEntry.ctbEntry.pTags))->len, pMeta->txn) < 0) {
@@ -2454,11 +2449,6 @@ static int metaUpdateTableTagVal(SMeta *pMeta, int64_t version, SVAlterTbReq *pA
     metaError("meta/table: failed to update tag idx:%s uid:%" PRId64, ctbEntry.name, ctbEntry.uid);
   }
 
-  if (NULL == ctbEntry.ctbEntry.pTags) {
-    metaError("meta/table: null tags, update tag val failed.");
-    goto _err;
-  }
-
   SCtbIdxKey ctbIdxKey = {.suid = ctbEntry.ctbEntry.suid, .uid = uid};
   if (tdbTbUpsert(pMeta->pCtbIdx, &ctbIdxKey, sizeof(ctbIdxKey), ctbEntry.ctbEntry.pTags,
                   ((STag *)(ctbEntry.ctbEntry.pTags))->len, pMeta->txn) < 0) {
diff --git a/source/libs/parser/src/parAstCreater.c b/source/libs/parser/src/parAstCreater.c
index e05a399d32..1217618c0a 100644
--- a/source/libs/parser/src/parAstCreater.c
+++ b/source/libs/parser/src/parAstCreater.c
@@ -2547,6 +2547,7 @@ SNode* createAlterSingleTagColumnNode(SAstCreateContext* pCtx, SToken* pTagName,
   pCtx->errCode = nodesMakeNode(QUERY_NODE_ALTER_TABLE_STMT, (SNode**)&pStmt);
   CHECK_MAKE_NODE(pStmt);
   pStmt->alterType = TSDB_ALTER_TABLE_UPDATE_TAG_VAL;
+  CHECK_NAME(checkColumnName(pCtx, pTagName));
   COPY_STRING_FORM_ID_TOKEN(pStmt->colName, pTagName);
   pStmt->pVal = (SValueNode*)pVal;
   pStmt->pNodeListTagValue = NULL;
diff --git a/tests/script/tsim/tag/change_multi_tag.sim b/tests/script/tsim/tag/change_multi_tag.sim
index 30ae1c653a..470b49d4dc 100644
--- a/tests/script/tsim/tag/change_multi_tag.sim
+++ b/tests/script/tsim/tag/change_multi_tag.sim
@@ -34,15 +34,34 @@ sql create table $ntable (ts timestamp, f int)
 
 sql insert into $tb values(now, 1)
 sql insert into $tb values(now, 1)
-sql_error alter table $mt set tag tgcol1 = 1,tagcol2 = 2, tag3 = 4 # set tag value on supertable
-sql_error alter table $ntable set tag f = 10  # set normal table value
-sql_error alter table $tbj set tag tagCol1=1,tagCol1 = 2 # dumplicate tag name
-sql_error alter table $tbj set tag tagCol1=1,tagCol1 = 2 # not exist tag
+
+# invalid sql
+sql_error  alter table $mt set tag tgcol1 = 1,
+sql_error  alter table $mt set tag ,
+sql_error  alter table $mt set tag tgcol1=10,tagcol2=
+#set tag value on supertable
+sql_error alter table $mt set tag tgcol1 = 1,tagcol2 = 2, tag3 = 4 
+#set normal table value
+sql_error alter table $ntable set tag f = 10
+# duplicate tag name
+sql_error alter table $tbj set tag tagCol1=1,tagCol1 = 2
+sql_error alter table $tbj set tag tagCol1=1,tagCol5=10, tagCol5=3
+# not exist tag
+sql_error alter table $tbj set tag tagNotExist = 1,tagCol1 = 2 
+sql_error alter table $tbj set tag tagCol1 = 2, tagNotExist = 1
+sql_error alter table $tbj set tagNotExist = 1
+sql_error alter table $tbj set tagNotExist = NULL,
 sql_error alter table $tbj set tag tagCol1 = 1, tagCol5="xxxxxxxxxxxxxxxx" 
+# invalid tag value
 sql_error alter table $tbj set tag tagCol1 = 1, tagCol5="xxxxxxxxxxxxxxxx", tagCol7="yyyyyyyyyyyyyyyyyyyyyyyyy" 
-sql_error alter table $tbj set tag tagCol1=1,tagCol5=10, tagCol1=3
-sql_error alter table $tbj set tag tagCol5="xxxx"
-sql alter table $tbj set tag tagCol1 = 100, tagCol2 = 100 
+# invalid data type
+
+# escape
+sql_error alter table $tbj set tag `tagCol1`=true
+sql_error alter table $tbj set tag `tagCol1`=true,`tagCol2`=1,`tagNotExist`=10
+sql_error alter table $tbj set tag `tagCol1`=true,`tagCol2`=1,tagcol1=true
+
+sql alter table $tbj set tag tagCol1 = 100, tagCol2 = 100  
 
 sql select * from $mt where tagCol2 = 100
 if $rows != 0  then
@@ -180,14 +199,16 @@ if $rows != 1  then
 endi
 
 sql alter table $tbj set tag tagCol1=true,tagCol2=-10,tagcol3=-100, tagcol4=-1000,tagcol5=NULL,tagCol6=NULL,tagCol7=NULL
+sql alter table $tbj set tag `tagcol1`=true,`tagcol2`=-10,`tagcol3`=-100, `tagcol4`=-1000,`tagcol5`=NULL,`tagcol6`=NULL,`tagcol7`=NULL
 
 sql alter table $mt drop tag tagCol7
 sql alter table $mt drop tag tagCol3
 
 sql alter table $mt add tag tagCol8 int
 
+#set not exist tag and value 
 sql_error alter table $tbj set tag tagCol1=true,tagCol2=-10,tagcol3=-100, tagcol4=-1000,tagcol5=NULL,tagCol6=NULL,tagCol7=NULL
-sql_error alter table $tbj set tag tagCol1=true,tagCol2=-10,tagcol3=-100, tagcol4=-1000,tagcol5=NULL,tagCol6=NULL,tagCol7=NULL
+sql_error alter table $tbj set tag tagCol1=true,tagCol2=-10,tagcol3=-100, tagcol4=-1000,tagcol5=NULL,tagCol6=NULL,tagCol7=NULL 
 
 sql alter table $tbj set tag tagCol8 = 8