继承控制器Frontend中添加：

application/common/contorller/Frontend.php

  /**
     * 自定义模板
     * @var string
     */
    protected $layouts = [];
    public function _initialize(){
        // 如果有使用模板布局
        $this->layout = $this->setLayout();
        if ($this->layout) {
            $this->view->engine->layout('layout/' . $this->layout);
        }

    }
     //多模板匹配
    public function getLayout(){
        if (!is_array($this->layouts)||empty($this->layouts)){
            return $this->layout;
        }
        $request= Request::instance();
        $action = $request->action();
        foreach ($this->layouts as $k=>$v){
            if (in_array($action, $v)){
                return $k;
            }
        }
        return $this->layout;
    }

    //自定义加载模块
    public function setLayout(){
        if (!is_array($this->layouts)||empty($this->layouts)){
            return $this->layout;
        }
        $request= Request::instance();
        $action = $request->action();
        foreach ($this->layouts as $k=>$v){
            if (in_array($action, $v)){
                return $k;
            }
        }
        return $this->layout;
    }

自定义控制器（例）：

application/index/contorller/User.php

class User extends Frontend{
    //设置默认模板，不需要则留空，仅加载自定义的模板
    protected $layout = 'default';
    //key：模板名称  value：对应使用该模板的所有方法名
    protected $layouts = ['a'=>['index'],'b'=>['profile','changepwd']];
}