这个json编码不编码都显示乱码 咋回事

if ($type == 'json2') {

        $headers = array("Content-type: application/json;charset=UTF-8", "Cache-Control: no-cache", "Pragma: no-cache");

        //$data = json_encode($data);

        $data = json_encode($data, JSON_UNESCAPED_UNICODE);

    }