逐个执行或者复制一键执行些命令 

echo root:kcxa@12345 |sudo chpasswd root

sudo -s

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

密码为kcxa@12345