方案A(稳定版+推荐)：
function replace_unicode_escape_sequence($match) {
    return mb_convert_encoding(pack('H*', $match[1]), 'UTF-8', 'UCS-2BE');
}
$name = '\u65b0\u6d6a\u5fae\u535a';
$str = preg_replace_callback('/\\\\u([0-9a-f]{4})/i', 'replace_unicode_escape_sequence', $name);
echo $str; //输出： 新浪微博 

   
//咱将上述方案A给封装起来~~~(方案A稳定版+升级+推荐)
class Helper_Tool
{
    static function unicodeDecode($data)
    {   
        function replace_unicode_escape_sequence($match) {
            return mb_convert_encoding(pack('H*', $match[1]), 'UTF-8', 'UCS-2BE');
        }   

        $rs = preg_replace_callback('/\\\\u([0-9a-f]{4})/i', 'replace_unicode_escape_sequence', $data);

        return $rs;
    }   
}
//调用
$name = '\u65b0\u6d6a\u5fae\u535a';
$data = Helper_Tool::unicodeDecode($name); //输出新浪微博


方案B(次推荐)：
<?php
function unicodeDecode($name){
    $json = '{"str":"'.$name.'"}';
    $arr = json_decode($json,true);
    if(empty($arr)) return ''; 
    return $arr['str'];
}
$name = '\u65b0\u6d6a\u5fae\u535a';
echo unicodeDecode($name); //输出： 新浪微博