diff --git a/services/reward/serial.go b/services/reward/serial.go
index a4679ebd4..a1e3d4c7e 100644
--- a/services/reward/serial.go
+++ b/services/reward/serial.go
@@ -21,7 +21,7 @@ func GetSerialNoByRedis() (string, error) {
 		redis_client.Expire(redis_key.RewardSerialCounter(now), 2*time.Minute)
 	}
 	//when the counter n exceeds 1000, the length of the serial number will become longer
-	if n > 1000 {
+	if n >= 1000 {
 		return now.Format("200601021504") + fmt.Sprintf("%d", n) + fmt.Sprint(rand.Intn(10)), nil
 	}
 	return now.Format("200601021504") + fmt.Sprintf("%03d", n) + fmt.Sprint(rand.Intn(10)), nil