$re = '/.*匡威.*\W([0-9a-zA-Z\-]{5,})\W/m';
$str = 'CONVERSE 匡威 男女 CONVERSE ALL STAR系列 Chuck Taylor All Star 休闲鞋 169444C 42码 US8.5码
CONVERSE 匡威 1970S 男女同款 CONVERSE ALL STAR系列 Chuck 70 帆布鞋 167635C 37.5码 US5码
CONVERSE 匡威 1970s 男女 CONVERSE ALL STAR系列 Chuck 70 休闲鞋 170090C 41码 US7.5码
CONVERSE 匡威 男女 配件系列 CAPS 运动 棒球帽 10018890-A10 OSFA码
CONVERSE匡威官方 All Star 男女鞋高帮运动休闲帆布鞋 1Z588 1Z588/黑色 41/7.5
CONVERSE匡威官方 All Star 男女鞋经典款高帮休闲情侣帆布鞋 101010 101010/黑色 35/3
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php