diff --git a/model/mysql_query_piece.go b/model/mysql_query_piece.go
index 7843436..19180c5 100644
--- a/model/mysql_query_piece.go
+++ b/model/mysql_query_piece.go
@@ -71,7 +71,7 @@ func (mqp *MysqlQueryPiece) GetSQL() (str *string) {
 }
 
 func (pmqp *PooledMysqlQueryPiece) Recovery() {
-	pmqp.recoverPool.Enqueue(pmqp)
 	pmqp.sliceBufferPool.Enqueue(pmqp.jsonContent[:0])
 	pmqp.jsonContent = nil
+	pmqp.recoverPool.Enqueue(pmqp)
 }
diff --git a/model/query_piece.go b/model/query_piece.go
index 440a664..e0d3a74 100644
--- a/model/query_piece.go
+++ b/model/query_piece.go
@@ -83,6 +83,10 @@ func (bqp *BaseQueryPiece) Recovery() {
 
 func marsharQueryPiece(qp interface{}) []byte {
 	var cacheBuffer = localSliceBufferPool.Dequeue()
+	if len(cacheBuffer) > 0 {
+		panic("there already have bytes in buffer")
+	}
+
 	buffer := bytes.NewBuffer(cacheBuffer)
 	err := json.NewEncoder(buffer).Encode(qp)
 	if err != nil {