ssh without change password
 

I have two server ( server A and server B ) , user in server A will ssh to serverB , I hv set the public key so that user do not need to input password when login serverB , but I found that serverB have policy to force user to change password regularly , so when the time the password is expired , the user is required to change password via the ssh login , can advise how to skip to ask user to change password if they use ssh to login ? thx

You'd have to adjust the policy on serverB... not sure if that's doable on a per-user basis, what are you using to enforce the password change? If pam, you should be able to set their account to never expire.

You can either check / remove the password expirey using the passwd command, man passwd should be all you need.
Also to check the policy you can look at /etc/login.defs.
You don't say for which distro so the above is true for Redhat/Cent/Fedora.
Login deeper you could check /etc/pam.d/system-auth and /etc/pam.d/sshd.
We are assuming here that your not using LDAP/Directory Server etc either.