thank you escrow.ms for your replay
the first time I choose the login way to "2-facter",the following option is "current password" /"new password" /"repeat new password",because I do not want to change my password so I leave these blank.then I input the 2-factor key into my phone's google authenticator,I got a 2-factor code,I though it finished,so I save,logout,login with 2-factor,fail,without 2-factor,sucsess.so I realized that It have not done.I try again,this time I choose "2-factor",fill in the "current password" /"new password" /"repeat new password",I noticed that there was a new 2-factor key on the page but I thought the setting on my phone was finished so I leave it alone.I think that was the mistake I made. I do have a 2-factor code on my phone but it does not match the web. I have not save the key or scan the QR code.It is too bad.I wish I could be more careful:(
Well you need to wait for support then and it's actually not your fault, it's their fault, they shouldn't include 2F with password change option in same page or atleast give warning when someone makes changes in 2factor authentication.
Ps: I have sent message to Graet.
https://bitcointalk.org/index.php?action=profile;u=17548I am not sure but i think he is owner of weexchange, so wait for his reply.