You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <allmessages>
      <message name="ipb-blockingself" xml:space="preserve">您将要封禁自己！确实要这样做吗？</message>
      <message name="ipb-blocklist" xml:space="preserve">查看现有封禁</message>
      <message name="ipb-blocklist-contribs" xml:space="preserve">$1的贡献</message>
      <message name="ipb-change-block" xml:space="preserve">使用这些设置重新封禁用户</message>
      <message name="ipb-confirm" xml:space="preserve">确认封禁</message>
      <message name="ipb-confirmhideuser" xml:space="preserve">您即将在封禁用户的同时启用“隐藏账户”功能。这将从所有列表和日志记录中隐藏这个用户名。您确认这样做吗？</message>
      <message name="ipb-default-expiry" xml:space="preserve" />
      <message name="ipb-disableusertalk" xml:space="preserve">阻止用户在封禁期间编辑自己的讨论页面</message>
      <message name="ipb-edit-dropdown" xml:space="preserve">编辑封禁原因</message>
      <message name="ipb-hardblock" xml:space="preserve">阻止登录用户使用该IP地址编辑</message>
      <message name="ipb-needreblock" xml:space="preserve">$1已被封禁。您是否想更改封禁设置？</message>
      <message name="ipb-otherblocks-header" xml:space="preserve">其他{{PLURAL:$1|封禁}}</message>
      <message name="ipb-unblock" xml:space="preserve">解封用户名或IP地址</message>
      <message name="ipb-unblock-addr" xml:space="preserve">解封$1</message>
    </allmessages>
  </query>
</api>