设置root用户密码

sudo passwd root

切换到root用户

su root

修改ssh配置文件

sed -ri 's/^#?(PasswordAuthentication)\s+(yes|no)/\1 yes/' /etc/ssh/sshd_config

sed -ri 's/^#?(PermitRootLogin)\s+(yes|no)/\1 yes/' /etc/ssh/sshd_config

sed -ri 's/^/#/;s/sleep 10"\s+/&\n/' /root/.ssh/authorized_keys

service sshd restart

touch /root/.Xauthority