1) vi /etc/ssh/sshd_config, change the value of PermitRootLogin to no, and save
2)service sshd restart
In this way, you can use root to disable ssh login.
Create a user to allow sudo privileges ------
Create a user eg: #useradd master
Set password: #passwd master
Add the master account with sudo permissions, as follows:
#visudo
join in
master ALL=(ALL) NOPASSWD: ALL