diff --git a/README.md b/README.md
index 0cab302..a21be19 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 <div align="center">
   <img width="500" style="max-width:100%" src="resource/static/brand.png" title="哪吒监控">
   <br><br>
-<img src="https://img.shields.io/github/workflow/status/naiba/nezha/Dashboard%20image?label=Dash%20v0.9.8&logo=github&style=for-the-badge">&nbsp;<img src="https://img.shields.io/github/v/release/naiba/nezha?color=brightgreen&label=Agent&style=for-the-badge&logo=github">&nbsp;<img src="https://img.shields.io/github/workflow/status/naiba/nezha/Agent%20release?label=Agent%20CI&logo=github&style=for-the-badge">&nbsp;<img src="https://img.shields.io/badge/Installer-v0.6.4-brightgreen?style=for-the-badge&logo=linux">
+<img src="https://img.shields.io/github/workflow/status/naiba/nezha/Dashboard%20image?label=Dash%20v0.9.9&logo=github&style=for-the-badge">&nbsp;<img src="https://img.shields.io/github/v/release/naiba/nezha?color=brightgreen&label=Agent&style=for-the-badge&logo=github">&nbsp;<img src="https://img.shields.io/github/workflow/status/naiba/nezha/Agent%20release?label=Agent%20CI&logo=github&style=for-the-badge">&nbsp;<img src="https://img.shields.io/badge/Installer-v0.6.4-brightgreen?style=for-the-badge&logo=linux">
   <br>
   <br>
   <p>:trollface: <b>哪吒监控</b> 一站式轻监控轻运维系统。支持系统状态、HTTP(SSL 证书变更、即将到期、到期)、TCP、Ping 监控报警，命令批量执行和计划任务。</p>	
diff --git a/service/dao/dao.go b/service/dao/dao.go
index 6a399e0..a47e711 100644
--- a/service/dao/dao.go
+++ b/service/dao/dao.go
@@ -13,7 +13,7 @@ import (
 	pb "github.com/naiba/nezha/proto"
 )
 
-var Version = "v0.9.8" // ！！记得修改 README 中的 badge 版本！！
+var Version = "v0.9.9" // ！！记得修改 README 中的 badge 版本！！
 
 var (
 	Conf  *model.Config
diff --git a/service/dao/servicesentinel.go b/service/dao/servicesentinel.go
index 5bfbc0c..9554966 100644
--- a/service/dao/servicesentinel.go
+++ b/service/dao/servicesentinel.go
@@ -132,6 +132,7 @@ func (ss *ServiceSentinel) Monitors() []model.Monitor {
 func (ss *ServiceSentinel) OnMonitorUpdate() {
 	var monitors []model.Monitor
 	DB.Find(&monitors)
+
 	ss.monitorsLock.Lock()
 	defer ss.monitorsLock.Unlock()
 	ss.monitors = make(map[uint64]model.Monitor)
@@ -145,14 +146,11 @@ func (ss *ServiceSentinel) OnMonitorUpdate() {
 		}
 	}
 
-	ss.monthlyStatusLock.Lock()
-	defer ss.monthlyStatusLock.Unlock()
 	year, month, day := time.Now().Date()
 	today := time.Date(year, month, day, 0, 0, 0, 0, time.Local)
 
-	// 加载历史记录
-	var mhs []model.MonitorHistory
-	DB.Where("created_at >= ? AND created_at < ?", today.AddDate(0, 0, -29), today).Find(&mhs)
+	ss.monthlyStatusLock.Lock()
+	defer ss.monthlyStatusLock.Unlock()
 	for i := 0; i < len(monitors); i++ {
 		ServiceSentinelShared.monthlyStatus[monitors[i].ID] = &model.ServiceItemResponse{
 			Monitor: monitors[i],
@@ -162,8 +160,13 @@ func (ss *ServiceSentinel) OnMonitorUpdate() {
 		}
 	}
 
-	// 整合数据
+	// 加载历史记录
+	var mhs []model.MonitorHistory
+	DB.Where("created_at >= ? AND created_at < ?", today.AddDate(0, 0, -29), today).Find(&mhs)
 	for i := 0; i < len(mhs); i++ {
+		if ServiceSentinelShared.monthlyStatus[mhs[i].MonitorID] == nil {
+			continue
+		}
 		dayIndex := 28 - (int(today.Sub(mhs[i].CreatedAt).Hours()) / 24)
 		if mhs[i].Successful {
 			ServiceSentinelShared.monthlyStatus[mhs[i].MonitorID].TotalUp++