安装cocoapods

1. 用brew更新Ruby

brew update
brew install ruby

2. 安装CocoaPods
   Mac OS X 10.11前

sudo gem install cocoapods

Mac OS X 10.11后

sudo gem install -n /usr/local/bin cocoapods

3. pod setup

mkdir -p ~/.cocoapods/repos/
cd ~/.cocoapods/repos
git clone https://github.com/CocoaPods/Specs.git master

更换源
gem sources --remove https://rubygems.org/
gem sources --add https://gems.ruby-china.com/
为了验证你的Ruby镜像是并且仅是ruby-china，执行以下命令查看
gem sources -l
如果是以下结果说明正确，如果有其他的请自行百度解决
*** CURRENT SOURCES ***
https://gems.ruby-china.com/

参考