$str = '$d=[{"_id":{"$id":"4fda7d42741d727c14000000"},"name":"\u519c\u592b\u5c71\u6cc9","bc":"123456","pic":"d: pic\water.jpg","aid":"232fd4df3"}]
$c=[{"_id":{"$id":"4fdaa7f3741d725816000000"},"bc":"012345678","name":"\u7ef4\u8fbe\u7eb8\u5dfe","cls":{"id":"125","name":"\u65e5\u7528\u54c1"},"std":{"name":"\u5f20\u6570","val":"10"}}]';
$str=preg_replace("#\\\u([0-9a-f]{4})#ie", "iconv('UCS-2BE', 'UTF-8', pack('H4', '\\1'))", $str);
echo $str;
乱码的话记得换下浏览器编码。