Can I migrate content between Macs more than once?

You should be able to use the migration assistant again, even if you have done it on your current computer. Go the link and follow the steps it provides to move your data to your new MacBook Air: https://support.apple.com/en-us/HT204350.

If it doesn't work then what you can also do is to get a usb stick, put the files on your MacBook Pro your want to transfer on there, put it into your MacBook Air, and put them on that computer. Make sure you have an USB type A to USB type C adapter if one of your MacBooks have USB A ports and not USB C ports.

Hope that helps.

Hi Gustav-Adolph,

If you want to merge your existing content with the content stored on your MacBook Pro, Snappycat8000 has the best answer.

If you want to first erase everything on your MacBook Air and then import the content from your MacBook Pro, erase your MacBook Air and reinstall macOS, then migrate your content when prompted in the Setup Assistant.

Use Disk Utility to erase an Intel-based Mac - Apple Support (CA)

Use Disk Utility to erase a Mac with Apple silicon - Apple Support (CA)