diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index acbf094555e72cb72fd096014be8e8a89d700f4c..bb124dec06e49be23f3a1572d8a878a694811977 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -492,10 +492,10 @@ 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);