mac os 執行終端機, 然後下指令，前提是要在app store先下載好os
#macOS Catalina 10.14.x 10.15.x sudo /Applications/Install\macOS\Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/你的usb名稱 #macOS High Sierra 10.13.x sudo /Applications/Install\macOS\High\Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/你的usb名稱 --applicationpath /Applications/Install\macOS\High\Sierra.app --nointeraction #macOS Sierra 10.12.x sudo /Applications/Install\macOS\Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/你的usb名稱 --applicationpath /Applications/Install\macOS\Sierra.app --nointeraction