diff --git a/service/controller/controller.go b/service/controller/controller.go
index 55fd334..4b347d5 100644
--- a/service/controller/controller.go
+++ b/service/controller/controller.go
@@ -109,6 +109,9 @@ func (c *Controller) Start() error {
 		Interval: time.Duration(c.config.UpdatePeriodic) * time.Second,
 		Execute:  c.userInfoMonitor,
 	}
+	if c.config.AutoSpeedLimitConfig == nil {
+		c.config.AutoSpeedLimitConfig = &AutoSpeedLimitConfig{0, 0, 0, 0}
+	}
 	if c.config.AutoSpeedLimitConfig.Limit > 0 {
 		c.limitedUsers = make(map[api.UserInfo]LimitInfo)
 		c.warnedUsers = make(map[api.UserInfo]int)