I arrive at 10.25pm on Saturday night. How do I get to Zhejiang university from Hangzhou Airport?

The university has several campuses. Do you refer to the Yuquan Campus located at No. 38 of Zheda Road?

If so, you can catch the airport shuttle bus Wulinmen Line and get off at Civil Aviation Ticket Office, the last stop of the bus line. Then take a taxi to the campus, about 2.3 miles far.

Thanks. But I thought that the airport shuttle ends at 8pm? And I only arrive at 10.25pm

No, it's not. Actually, shuttle bus Wulinmen line operates till the arrival of the last flight, much later than 10:25pm. So you can surely catch it upon arrival. No need to get worried.