I want to go to Guilin Liangjiang Airport using a bus.

Do you refer to the Jijinling Campus of the university? If yes, from the campus, take public bus no.16 from Jinji Crossing to Anxin Community Bus Stop first. Then walk south around 550 yards to Civil Aviation Hotel. Then you can find several shuttle buses that can take you to the terminal building directly. The operating hours of this bus line are from 06:00 to 21:30 with the frequency of around half an hour. The ticket fare is CNY 20 per person.