diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index 9893533a589af0ca7a87dd05628db5059ecbe8eb..65a00202835dab41c5a526645c35a7fdb4692794 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -490,10 +490,10 @@ void tsBufAppend(STSBuf* pTSBuf, int32_t id, tVariant* tag, const char* pData, i
 }
 
 void tsBufFlush(STSBuf* pTSBuf) {
-  if (pTSBuf->tsData.len <= 0) {
+  if (pTSBuf->numOfGroups <= 0) {
     return;
   }
-  
+
   writeDataToDisk(pTSBuf);
   shrinkBuffer(&pTSBuf->tsData);