找到soure/function/function_forum.php
第573行取消即可
if(empty($_G['uid'])) {
  $_G['group']['allowpostactivity'] = $_G['group']['allowpostpoll'] = $_G['group']['allowvote'] = $_G['group']['allowpostreward'] = $_G['group']['allowposttrade'] = $_G['group']['allowpostdebate'] = $_G['group']['allowpostrushreply'] = 0;
}