参考视频：https://www.youtube.com/watch?v=iHcxszAmqOI

在百度网盘里面搜索：OS X 10.11 El Capitan GM by TechReviews

下载下面这些文件：

OS X 10.11 El Capitan GM by TechReviews.part01.rar

OS X 10.11 El Capitan GM by TechReviews.part02.rar

OS X 10.11 El Capitan GM by TechReviews.part03.rar

OS X 10.11 El Capitan GM by TechReviews.part04.rar

OS X 10.11 El Capitan GM by TechReviews.part05.rar

OS X 10.11 El Capitan GM by TechReviews.part06.rar

OS X 10.11 El Capitan GM by TechReviews.part07.rar

解压，得到OS X 10.11 El Capitan GM by TechReviews.vmdk

#!/bin/sh

VBoxManage modifyvm "OS X Name" --cpuidset 00000001 000306a9 04100800 7fbae3ff bfebfbff
VBoxManage setextradata "OS X Name" "VBoxInternal/Devices/efi/0/Config/DmiSystemProduct" "MacBookPro11,3"
VBoxManage setextradata "OS X Name" "VBoxInternal/Devices/efi/0/Config/DmiSystemVersion" "1.0"
VBoxManage setextradata "OS X Name" "VBoxInternal/Devices/efi/0/Config/DmiBoardProduct" "Iloveapple"
VBoxManage setextradata "OS X Name" "VBoxInternal/Devices/smc/0/Config/DeviceKey" "ourhardworkbythesewordsguardedpleasedontsteal(c)AppleComputerInc"
VBoxManage setextradata "OS X Name" "VBoxInternal/Devices/smc/0/Config/GetKeyFromRealSMC" 1

将上面的内容中的OS X Name全部替换成您的虚拟机的名称，然后保存成install.sh

修改为可执行权限，并执行：

chmod a+x install.sh
./install.sh