修改方法（注意备份）：

do/search.php

找到

$query = $db->query("SELECT {$_moduleSqlSearch}B.*,A.* FROM {$pre}article$erp A LEFT JOIN {$pre}reply B ON A.aid=B.aid $_moduleSql WHERE $SQL $_SQL ORDER BY A.aid DESC LIMIT $min,$rows");

改成

if($mid>='100'){
  //如果搜索模型才进行表连接
$query = $db->query("SELECT {$_moduleSqlSearch}B.*,A.*,D.* FROM {$pre}article$erp A LEFT JOIN {$pre}reply B ON A.aid=B.aid LEFT JOIN {$pre}article_content_$mid D ON B.aid=D.aid $_moduleSql WHERE $SQL $_SQL ORDER BY A.aid DESC LIMIT $min,$rows");
}else{
  $query = $db->query("SELECT {$_moduleSqlSearch}B.*,A.* FROM {$pre}article$erp A LEFT JOIN {$pre}reply B ON A.aid=B.aid $_moduleSql WHERE $SQL $_SQL ORDER BY A.aid DESC LIMIT $min,$rows");}