diff --git a/main.go b/main.go
index 474ca41..7b91a2b 100644
--- a/main.go
+++ b/main.go
@@ -21,7 +21,7 @@ func testParseCert() {
 	// 读取
 	dir := src.GetAppConfig().CertDir
 	dir = filepath.Join(dir, "acme.zzzykj.cn")
-	certFile := path.Join(dir, "cert.crt")
+	certFile := path.Join(dir, src.CertFileName)
 	certBytes, err := os.ReadFile(certFile)
 	if err != nil {
 		panic(err)
diff --git a/src/acme-client.go b/src/acme-client.go
index 0c45dfc..3d1db80 100644
--- a/src/acme-client.go
+++ b/src/acme-client.go
@@ -99,12 +99,12 @@ func saveCertFile(cert *certificate.Resource, name string) {
 	}
 
 	certBytes := cert.Certificate
-	err = os.WriteFile(path.Join(dir, "cert.crt"), certBytes, 0755)
+	err = os.WriteFile(path.Join(dir, CertFileName), certBytes, 0755)
 	if err != nil {
 		log.Fatalf("Failed to save certificate: %v", err)
 	}
 
-	err = os.WriteFile(path.Join(dir, "cert.key"), cert.PrivateKey, 0755)
+	err = os.WriteFile(path.Join(dir, KeyFileName), cert.PrivateKey, 0755)
 	if err != nil {
 		log.Fatalf("Failed to save private key: %v", err)
 	}
@@ -128,7 +128,7 @@ func saveCertFile(cert *certificate.Resource, name string) {
 	if err != nil {
 		log.Fatalf("Failed to marshal certificate: %v", err)
 	}
-	err = os.WriteFile(path.Join(dir, "info.json"), certJson, 0644)
+	err = os.WriteFile(path.Join(dir, CertInfoFileName), certJson, 0644)
 	if err != nil {
 		log.Fatalf("Failed to save certificate info: %v", err)
 	}
diff --git a/src/http.go b/src/http.go
index 871a6ff..8eb4ec1 100644
--- a/src/http.go
+++ b/src/http.go
@@ -43,7 +43,7 @@ func getCert(c *gin.Context) {
 		})
 		return
 	}
-	crtFilePath := path.Join(dir, "cert.crt")
+	crtFilePath := path.Join(dir, CertFileName)
 	crtContent, err := os.ReadFile(crtFilePath)
 	if err != nil {
 		c.JSON(200, gin.H{
@@ -54,7 +54,7 @@ func getCert(c *gin.Context) {
 	}
 	crt := string(crtContent)
 
-	keyFilePath := path.Join(dir, "cert.key")
+	keyFilePath := path.Join(dir, KeyFileName)
 	keyContent, err := os.ReadFile(keyFilePath)
 	if err != nil {
 		c.JSON(200, gin.H{
diff --git a/src/task.go b/src/task.go
index 57256b0..15abff1 100644
--- a/src/task.go
+++ b/src/task.go
@@ -1,7 +1,79 @@
 package src
 
-import "log"
+import (
+	"encoding/json"
+	"log"
+	"os"
+	"path"
+	"time"
+)
+
+var AutoRefreshCertTicker = time.NewTicker(time.Hour)
 
 func AutoRefreshCert() {
 	log.Println("Start auto refresh cert")
+	defer AutoRefreshCertTicker.Stop()
+	for {
+		select {
+		case <-AutoRefreshCertTicker.C:
+			doRefreshCert()
+		}
+	}
+}
+
+func doRefreshCert() {
+	domains := GetAppConfig().Domains
+	for _, domain := range domains {
+		doRefreshCertOnce(domain)
+	}
+}
+
+func doRefreshCertOnce(domain Domain) {
+	name := domain.Name
+	dir := GetAppConfig().CertDir
+	certDir := path.Join(dir, name)
+	// 判断文件夹和证书文件是否存在
+	_, err := os.Stat(certDir)
+	if os.IsNotExist(err) {
+		log.Println("Applying for a certificate, Domain: {} certificate directory does not exist!", name)
+		Apply(domain)
+		return
+	}
+	if existFile(certDir, CertFileName) {
+		log.Println("Applying for a certificate, Domain: {} {} does not exist!", name, CertFileName)
+		Apply(domain)
+		return
+	}
+	if existFile(certDir, KeyFileName) {
+		log.Println("Applying for a certificate, Domain: {} {} does not exist!", name, KeyFileName)
+		Apply(domain)
+		return
+	}
+	if existFile(certDir, CertInfoFileName) {
+		log.Println("Applying for a certificate, Domain: {} {} does not exist!", name, CertInfoFileName)
+		Apply(domain)
+		return
+	}
+	infoFile := path.Join(dir, CertInfoFileName)
+	infoBytes, err := os.ReadFile(infoFile)
+	if err != nil {
+		log.Println("Failed to read cert info file, Domain: {}", name)
+	}
+	var certInfo CertInfo
+	err = json.Unmarshal(infoBytes, &certInfo)
+	if err != nil {
+		log.Println("Failed to parse cert info file, Domain: {}", name)
+	}
+	log.Println("Checking if the certificate is expired, Domain: {}", name)
+	if certInfo.Info.NotAfter.Sub(time.Now()) < 7*24*time.Hour {
+		log.Println("Apply for a certificate that is about to expire, domain name:", name)
+		Apply(domain)
+	}
+}
+
+func existFile(dir string, fileName string) bool {
+	f := path.Join(dir, fileName)
+	_, err := os.Stat(f)
+	return !os.IsNotExist(err)
+
 }
diff --git a/src/variable.go b/src/variable.go
index cfa704e..02a1069 100644
--- a/src/variable.go
+++ b/src/variable.go
@@ -3,6 +3,10 @@ package src
 const PidFile = "acme-mana.pid"
 const SocketFile = "acme-mana.sock"
 
+const CertFileName = "fullchain.pem"
+const KeyFileName = "privkey.pem"
+const CertInfoFileName = "info.json"
+
 var appConfig AppConfig = ReadConfig()
 
 func GetAppConfig() AppConfig {