diff --git a/auth.go b/auth.go
index 883732e..56f5f33 100644
--- a/auth.go
+++ b/auth.go
@@ -75,18 +75,22 @@ func (cli *Client) AccessToken() (string, error) {
 		return data.(string), nil
 	}
 
-	rsp, err := cli.GetAccessToken()
-	if err != nil {
-		return "", err
-	}
-
-	if err := rsp.GetResponseError(); err != nil {
-		return "", err
+	if cli.accessTokenGetter != nil {
+		token, expireIn := cli.accessTokenGetter()
+		cli.cache.Set(key, token, time.Duration(expireIn))
+		return token, nil
+	} else {
+		rsp, err := cli.GetAccessToken()
+		if err != nil {
+			return "", err
+		}
+
+		if err := rsp.GetResponseError(); err != nil {
+			return "", err
+		}
+		cli.cache.Set(key, rsp.AccessToken, time.Duration(rsp.ExpiresIn))
+		return rsp.AccessToken, nil
 	}
-
-	cli.cache.Set(key, rsp.AccessToken, time.Duration(rsp.ExpiresIn))
-
-	return rsp.AccessToken, nil
 }
 
 func (cli *Client) GetAccessToken() (*TokenResponse, error) {
diff --git a/weapp.go b/weapp.go
index 0fd1448..eca8664 100644
--- a/weapp.go
+++ b/weapp.go
@@ -36,8 +36,13 @@ type Client struct {
 	appid string
 	// 小程序后台配置: 小程序密钥
 	secret string
+	// 用户自定义获取access_token的方法
+	accessTokenGetter AccessTokenGetter
 }
 
+// 用户自定义获取access_token的方法
+type AccessTokenGetter func() (token string, expireIn uint)
+
 // 初始化客户端并用自定义配置替换默认配置
 func NewClient(appid, secret string, opts ...func(*Client)) *Client {
 	cli := &Client{
@@ -83,6 +88,13 @@ func WithCache(cc cache.Cache) func(*Client) {
 	}
 }
 
+// 自定义获取access_token的方法
+func WithAccessTokenSetter(getter AccessTokenGetter) func(*Client) {
+	return func(cli *Client) {
+		cli.accessTokenGetter = getter
+	}
+}
+
 // 自定义日志
 func WithLogger(logger logger.Logger) func(*Client) {
 	return func(cli *Client) {