❶:hdiutil create -o /tmp/Catalina -size 9000m -volname Catalina -layout SPUD -fs JHFS+
❷:hdiutil attach /tmp/Catalina.dmg -noverify -mountpoint /Volumes/Catalina
❸:sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia –volume /Volumes/Catalina –nointeraction
❹:hdiutil detach /volumes/Install\ macOS\ Catalina
❺:hdiutil convert /tmp/Catalina.dmg -format UDTO -o ~/Desktop/Catalina.cdr
❻:mv ~/Desktop/Catalina.cdr ~/Desktop/Catalina.iso
❼:rm /tmp/Catalina.dmg
![](https://blog.tiansam.net/wp-content/uploads/2020/03/image.png)
![](https://blog.tiansam.net/wp-content/uploads/2020/03/image-1.png)