sudo nano /etc/ntp.conf

然后找到

# pool.ntp.org maps to about 1000 low-stratum NTP servers. Your server will

# pick a different set every time it starts up. Please consider joining the

# pool: <http://www.pool.ntp.org/join.html>

server 0.debain.pool.ntp.org iburst

server 1.debain.pool.ntp.org iburst

server 2.debain.pool.ntp.org iburst

server 3.debain.pool.ntp.org iburst

或者类似的东西，把它改成

# pool.ntp.org maps to about 1000 low-stratum NTP servers. Your server will

# pick a different set every time it starts up. Please consider joining the

# pool: <http://www.pool.ntp.org/join.html>

server asia.pool.ntp.org iburst

重启即可

原理： 原来的NTP服务器pool（提供服务器名称的网站）貌似被墙了，因此改成这样（asia.pool.ntp.org）