diff --git a/pkg/gateway/lb/handler/grpc/handler.go b/pkg/gateway/lb/handler/grpc/handler.go
index 6c1da5a4853..e5b77f46c33 100644
--- a/pkg/gateway/lb/handler/grpc/handler.go
+++ b/pkg/gateway/lb/handler/grpc/handler.go
@@ -1837,8 +1837,8 @@ func (s *server) Update(ctx context.Context, req *payload.Update_Request) (res *
 			return nil, err
 		}
 		if conv.F32stos(vec.GetVector()) == conv.F32stos(req.GetVector().GetVector()) {
-			if req.GetConfig().GetUpdateTimestampIfExists() && vec.Timestamp == req.GetConfig().GetTimestamp() {
-				// if the vector is the same, broadcast update request to update index timestamp
+			if req.GetConfig().GetUpdateTimestampIfExists() && vec.Timestamp < req.GetConfig().GetTimestamp() {
+				// if the request vector timestamp is lager than existed one, broadcast update request to update index timestamp
 				return broadcastUpdate()
 			}
 			if err == nil {