解决方法：修改hosts
1、打开文件： C:\Windows\System32\drivers\etc\hosts
2、在文件末尾添加：
# GitHub Start
140.82.113.3 github.com
140.82.114.20 gist.github.com
151.101.184.133 assets-cdn.github.com
151.101.184.133 raw.githubusercontent.com
151.101.184.133 gist.githubusercontent.com
151.101.184.133 cloud.githubusercontent.com
151.101.184.133 camo.githubusercontent.com
151.101.184.133 avatars0.githubusercontent.com
199.232.68.133 avatars0.githubusercontent.com
199.232.28.133 avatars1.githubusercontent.com
151.101.184.133 avatars1.githubusercontent.com
151.101.184.133 avatars2.githubusercontent.com
199.232.28.133 avatars2.githubusercontent.com
151.101.184.133 avatars3.githubusercontent.com
199.232.68.133 avatars3.githubusercontent.com
151.101.184.133 avatars4.githubusercontent.com
199.232.68.133 avatars4.githubusercontent.com
151.101.184.133 avatars5.githubusercontent.com
199.232.68.133 avatars5.githubusercontent.com
151.101.184.133 avatars6.githubusercontent.com
199.232.68.133 avatars6.githubusercontent.com
151.101.184.133 avatars7.githubusercontent.com
199.232.68.133 avatars7.githubusercontent.com
151.101.184.133 avatars8.githubusercontent.com
199.232.68.133 avatars8.githubusercontent.com
# GitHub End
3、保存文件即可。