Xcode 9.4.1
https://download.developer.apple.com/Developer_Tools/Xcode_9.4.1/Xcode_9.4.1.xip
Xcode 9.4
https://download.developer.apple.com/Developer_Tools/Xcode_9.4/Xcode_9.4.xip
Xcode 9.3.1
https://download.developer.apple.com/Developer_Tools/Xcode_9.3.1/Xcode_9.3.1.xip
Xcode 9.3
https://download.developer.apple.com/Developer_Tools/Xcode_9.3/Xcode_9.3.xip
Xcode 9.2
https://download.developer.apple.com/Developer_Tools/Xcode_9.2/Xcode_9.2.xip
Xcode 9.1
https://download.developer.apple.com/Developer_Tools/Xcode_9.1/Xcode_9.1.xip
Xcode 9.0.1
https://download.developer.apple.com/Developer_Tools/Xcode_9.0.1/Xcode_9.0.1.xip
Xcode 9
https://download.developer.apple.com/Developer_Tools/Xcode_9/Xcode_9.xip
Xcode 8.3.3
https://download.developer.apple.com/Developer_Tools/Xcode_8.3.3/Xcode8.3.3.xip
Xcode 8.3.2
https://download.developer.apple.com/Developer_Tools/Xcode_8.3.2/Xcode8.3.2.xip
Xcode 8.3.1
https://download.developer.apple.com/Developer_Tools/Xcode_8.3.1/Xcode_8.3.1.xip
链接提取方法请参考我的CSDN文章
https://blog.csdn.net/annkie/article/details/48625519
官方离线下载地址入口
https://developer.apple.com/download/more/
Xcode 10.1 (xip) 官方直接下载地址(离线下载）
### Xcode 10.1
https://download.developer.apple.com/Developer_Tools/Xcode_10.1/Xcode_10.1.xip
### Xcode 10
https://download.developer.apple.com/Developer_Tools/Xcode_10/Xcode_10.xip
### Xcode 9.4.1
https://download.developer.apple.com/Developer_Tools/Xcode_9.4.1/Xcode_9.4.1.xip
### Xcode 9.4
https://download.developer.apple.com/Developer_Tools/Xcode_9.4/Xcode_9.4.xip
Xcode 9.3
http://adcdownload.apple.com/Developer_Tools/Xcode_9.3/Xcode_9.3.xip
Xcode 8.3.1
http://adcdownload.apple.com/Developer_Tools/Xcode_8.3.1/Xcode_8.3.1.xip
Xcode 8.2.1
http://adcdownload.apple.com/Developer_Tools/Xcode_8.2.1/Xcode_8.2.1.xip
Xcode 8.2
http://adcdownload.apple.com/Developer_Tools/Xcode_8.2/Xcode_8.2.xip
Xcode 8.1
http://adcdownload.apple.com/Developer_Tools/Xcode_8.1/Xcode_8.1.xip
Xcode 8.0
http://adcdownload.apple.com/Developer_Tools/Xcode_8/Xcode_8.xip
Xcode 7
7.3.1:https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_7.3.1/Xcode_7.3.1.dmg
7.3: https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_7.3/Xcode_7.3.dmg
7.2.1:https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_7.2.1/Xcode_7.2.1.dmg
7.2 : https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_7.2/Xcode_7.2.dmg
7.1.1: https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_7.1.1/Xcode_7.1.1.dmg
7.1 : https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_7.1/Xcode_7.1.dmg
7.0 : https://developer.apple.com/services-account/download?path=/Developer_Tools/Xcode_7/Xcode_7.dmg
我把获取离线下载地址的方法贴出来：(官方地址已经变更：https://developer.apple.com/download/more/）
OS X dmg地址可以拼装出来，但是好像需要开发者账号才能下载。
比如：OS X 10.11
https://developer.apple.com/services-account/download?path=/Developer_Tools/OS_X/OS_X_Yosemite_10.11_build_15A178W/OSX10.11.dmg
https://developer.apple.com/services-account/download?path=/Developer_Tools/OS_X/OS_X_Yosemite_10.11_build_15A178W/OSXUpd10.11.dmg
Xcode 8.2.1
http://adcdownload.apple.com/Developer_Tools/Xcode_8.2.1/Xcode_8.2.1.xip
Xcode 8.2.1
http://adcdownload.apple.com/Developer_Tools/Xcode_8.2.1/Xcode_8.2.1.xip
参考文档: