diff --git a/src/kit/taosdemo/taosdemo.c b/src/kit/taosdemo/taosdemo.c
index d04bb2905f0d67c8614cd7594a1aa84213752964..d98d5bdf0b1ad8e7cb89e939c8cee60940af2366 100644
--- a/src/kit/taosdemo/taosdemo.c
+++ b/src/kit/taosdemo/taosdemo.c
@@ -5181,7 +5181,7 @@ static int64_t generateStbRowData(
             dataLen += 1;
         }
 
-        if (dataLen > remainderBufLen)
+        if (dataLen > (remainderBufLen - (DOUBLE_BUFF_LEN + 1)))
             return 0;
     }