解决办法:将3个字节的特殊字符与emoji表情替换掉即可。
$nickname = preg_replace('/xE0[x80-x9F][x80-xBF]'.'|xED[xA0-xBF][x80-xBF]/S','?', $nickname ); $nickname = preg_replace('/xEE[x80-xBF][x80-xBF]|xEF[x81-x83][x80-xBF]/', '', $nickname);