diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index 7c2f8ebb5eb598205eb0c8b9f48c10c80a687bfb..fa8f83e4dc71485afc88c8977b1ab54dbb06f64b 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -974,7 +974,7 @@ int32_t tsBufGetNumOfVnodes(STSBuf* pTSBuf) {
     return 0;
   }
 
-  return pTSBuf->pData->len;
+  return pTSBuf->numOfVnodes;
 }
 
 void tsBufGetVnodeIdList(STSBuf* pTSBuf, int32_t* num, int32_t** vnodeId) {