Xi'an airport to city center

Yes, you can still take the airport shuttle bus Xishaomen Line to downtown area. The operating hours of this bus line will operate until the last flight arrival.

Thank you for your prompt reply.
Where do I catch the bus when I exit the international airport? Do I pay in the bus or do I have to purchase the tickets at counters inside the airport?
Lastly, is it safe to walk to my hotel after midnight like 1.30 a.m, meaning there will be people walking on the street or will the road be deserted? I am staying at Skytel which is about 20 mins walk from Xian Hotel which I believe is where the shuttle bus will stop.
Thank you.

The boarding site of shuttle buses is located at the Ground Transportation Center. You need to purchase the tickets at the ticket booth nearby the boarding site. After arriving, you can see many detailed English signs at the airport that will guide you to the right place. Generally speaking, you don't need to worry about the safety problem.