根据你的描述应该是你伪静态规则不正确。
下面是标准程序,lamp环境下的标准伪静态规则。如果你的discuz在根目录可以直接复制做成.htaccess文件,上传使用即可正常。
# 将 RewriteEngine 模式打开RewriteEngine On
# 修改以下语句中的 /discuz 为您的论坛目录地址,如果程序放在根目录中,请将 /discuz 修改为 /
RewriteBase /
# Rewrite 系统规则请勿修改
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^topic-(.+)\.html$ portal.php?mod=topic&topic=$1&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^article-([0-9]+)-([0-9]+)\.html$ portal.php?mod=view&aid=$1&page=$2&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^forum-(\w+)-([0-9]+)\.html$ forum.php?mod=forumdisplay&fid=$1&page=$2&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^thread-([0-9]+)-([0-9]+)-([0-9]+)\.html$ forum.php?mod=viewthread&tid=$1&extra=page\%3D$3&page=$2&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^group-([0-9]+)-([0-9]+)\.html$ forum.php?mod=group&fid=$1&page=$2&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^space-(username|uid)-(.+)\.html$ home.php?mod=space&$1=$2&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^blog-([0-9]+)-([0-9]+)\.html$ home.php?mod=space&uid=$1&do=blog&id=$2&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^archiver/(fid|tid)-([0-9]+)\.html$ archiver/index.php?action=$1&value=$2&%1
RewriteCond %{QUERY_STRING} ^(.*)$
RewriteRule ^([a-z]+[a-z0-9_]*)-([a-z0-9_\-]+)\.html$ plugin.php?id=$1:$2&%1