看到输出UTF-16？有点卡住

这将转换为UTF-8：

function unescape_utf16($string) {
    /* go for possible surrogate pairs first */
    $string = preg_replace_callback(
        '/\\\\u(D[89ab][0-9a-f]{2})\\\\u(D[c-f][0-9a-f]{2})/i',
        function ($matches) {
            $d = pack("H*", $matches[1].$matches[2]);
            return mb_convert_encoding($d, "UTF-8", "UTF-16BE");
        }, $string);
    /* now the rest */
    $string = preg_replace_callback('/\\\\u([0-9a-f]{4})/i',
        function ($matches) {
            $d = pack("H*", $matches[1]);
            return mb_convert_encoding($d, "UTF-8", "UTF-16BE");
        }, $string);
    return $string;
}