diff --git a/backend/database/redis.go b/backend/database/redis.go
index bc6b4982..d93491f8 100644
--- a/backend/database/redis.go
+++ b/backend/database/redis.go
@@ -107,7 +107,7 @@ func (r *Redis) HKeys(collection string) ([]string, error) {
 	c := r.pool.Get()
 	defer utils.Close(c)
 
-	value, err2 := redis.Strings(c.Do("HKeys", collection))
+	value, err2 := redis.Strings(c.Do("HKEYS", collection))
 	if err2 != nil {
 		log.Error(err2.Error())
 		debug.PrintStack()
@@ -208,7 +208,7 @@ func (r *Redis) Lock(lockKey string) (int64, error) {
 		debug.PrintStack()
 		return 0, err
 	}
-	if err == nil && ok == nil {
+	if ok == nil {
 		log.Errorf("the lockKey is locked: key=%s", lockKey)
 		return 0, errors.New("the lockKey is locked")
 	}
diff --git a/backend/model/user.go b/backend/model/user.go
index ba693cd9..feb801cb 100644
--- a/backend/model/user.go
+++ b/backend/model/user.go
@@ -54,17 +54,13 @@ func (user *User) Add() error {
 	// 如果存在用户名相同的用户，抛错
 	user2, err := GetUserByUsername(user.Username)
 	if err != nil {
-		if err == mgo.ErrNotFound {
-			// pass
-		} else {
-			log.Errorf(err.Error())
-			debug.PrintStack()
-			return err
-		}
-	} else {
-		if user2.Username == user.Username {
-			return errors.New("username already exists")
-		}
+		log.Errorf(err.Error())
+		debug.PrintStack()
+		return err
+	}
+
+	if user2.Username == user.Username {
+		return errors.New("username already exists")
 	}
 
 	user.Id = bson.NewObjectId()