How do i travel from airport to Citadines Central Xian in Bei Lin District by Metro?

Well, there is no subway station in the airport nowadays.
You can take shuttle bus East Street Line and get to Grand Metropark Hotel first. The operating hours are from 08:30 to 20:30. It takes around an hour. And the ticket fare is CNY 25 per person. After arriving, take a cab to the destination. It would cost around CNY 11 in the day time.

Thank you Mila for reply.