方案一：

访问：http://tool.chinaz.com/dns?type=1&host=www.github.com&ip=

获取 TTL 最小的值，添加进 hosts ：
192.30.255.113 github.com

方案二（不推荐）：

在C:\Windows\System32\drivers\etc\hosts 文件中增加以下内容：

140.82.112.4 github.com
140.82.113.3 gist.github.com
185.199.108.153 assets-cdn.github.com
199.232.68.133 raw.githubusercontent.com
199.232.68.133 gist.githubusercontent.com
199.232.68.133 cloud.githubusercontent.com
151.101.192.133 camo.githubusercontent.com
199.232.68.133 avatars0.githubusercontent.com
199.232.68.133 avatars1.githubusercontent.com
199.232.68.133 avatars2.githubusercontent.com
199.232.68.133 avatars3.githubusercontent.com
199.232.68.133 avatars4.githubusercontent.com
199.232.68.133 avatars5.githubusercontent.com
199.232.68.133 avatars6.githubusercontent.com
199.232.68.133 avatars7.githubusercontent.com
199.232.68.133 avatars8.githubusercontent.com