WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is。。。。。

Add correct host key in C:\\Users\\John/.ssh/known_hosts to get rid of this message.
Offending RSA key in C:\\Users\\John/.ssh/known_hosts:1

重装了系统再用powershell/cmd  ssh 远程的时候会出现上面的东西，仔细看是用户文件夹下有个.ssh 的文件，记录了原来的RSA，把这个文件删了或者重命名一下就可以了。