refer to: https://serverfault.com/questions/407033/how-can-i-edit-the-welcome-message-when-ssh-start
编辑 /etc/motd
内容如下
< 欢迎来到测试服务器” >
-------------------------
\
\
.--.
|o_o |
|:_/ |
// \ \
(| | )
/'\_ _/`\
\___)=(___/
< 欢迎来到测试服务器” >
效果如下:

asc ii 图片的来源
https://tool.lu/asciipainting/index.html?q=Birthday
到这里直接复制粘贴