此nginx重写规则哪里不对？

[fanstast]

访问
http://域名/wp-content/themes/wpdx/timthumb.php?src=http://img.acgget.com/up/2015/08/t01b8994cf01334e9ef.jpg&h=330&w=930&zc=1
重写规则

rewrite ^/images/(.*)_(.*)/(.*).(jpeg|png|jpg|gif)$			/wp-content/themes/wpdx/timthumb.php?src=http://$host/$1 last;

访问还是没有重写链接，就像规则没生效一样。