参考链接：
http://blog.coinidea.com/web%E5%BC%80%E5%8F%91/php-1196.html

// Filter 英文标点符号
$word = preg_replace("/[[:punct:]]/i"," ",$word);
 
// Filter 中文标点符号
mb_regex_encoding('utf-8');
$char = "。、！？：；﹑•＂…‘’“”〝〞∕¦‖—　〈〉﹞﹝「」‹›〖〗】【»«』『〕〔》《﹐¸﹕︰﹔！¡？¿﹖﹌﹏﹋＇´ˊˋ―﹫︳︴¯＿￣﹢﹦﹤‐­˜﹟﹩﹠﹪﹡﹨﹍﹉﹎﹊ˇ︵︶︷︸︹︿﹀︺︽︾ˉ﹁﹂﹃﹄︻︼（）";
$word = mb_ereg_replace("[".$char."]"," ",$word,"UTF-8");
 
// Filter 连续空格
$word = preg_replace("/\s+/"," ",$word);

mb_ereg_replace用于中文字符替换，正则的时候不需要加/ /。

参考链接：
http://blog.coinidea.com/web%E5%BC%80%E5%8F%91/php-1196.html