- mb_convert_encoding: documentation ( source)
- urldecode: documentation ( source)
<?php
$param = "%E7%91%9E%E6%80%9D%E5%AD%A6%E7%A7%91%E8%8B%B1%E8%AF%AD";
echo iconv("GBK", "UTF-8", urldecode($param));
echo mb_convert_encoding(urldecode($param), "utf-8", "gb2312");