Can I spend the night at the Hong Kong airport after customs clearance?

In order not to affect your exam, I still suggest you find a hotel. If the hotel next to the airport is expensive or full, try to find one outside. It takes more than an hour to get out of the city by subway from the airport, which is acceptable. There will be many youth hostels near Causeway Bay and Wan Chai, where you can spend the night.

The airport can also spend the night, but after all, it is a public place, so it is inconvenient for you to sleep and the seat is uncomfortable. People passing by will also affect the quality of sleep.