后台新建个 sitemap栏目
把sitemap.php文件当成模版
sitemap模版文件内容如下：

<?php echo'<?xml version="1.0" encoding="utf-8"?>'; ?>

<?php echo'<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">'; ?>

{{$channels=c(0,99999,0,1)}}

{{loop $channels as $channel}}

<url>

  <loc>http://www.u4v.cn{{$channel['url']}}</loc>

  <changefreq>daily</changefreq>

  <priority>1.0</priority>

</url>

{{/loop}}

{{$channels=c(0,99999,0,1)}}

{{loop $channels as $channel}}

{{$set=array()}}  

{{$set['cid']=$channel['cid']}}  

{{$set['pagesize']=99999}}  

{{$set['order']='shijian desc'}}  

{{$articles=alist($set)}}  

{{loop $articles['list'] as $a}}

  <url>

  <loc>http://www.u4v.cn{{$a['link']}}</loc>

  <lastmod>{{$a['shijian']|date('Y-m-d H:i:s',this)}} </lastmod>

  <changefreq>monthly</changefreq>

   <priority>0.8</priority>

  </url>

{{/loop}}

{{/loop}}

</urlset>

访问：http://www.u4v.cn/sitemap.xml