You can see the airport bus when you leave the departure hall of the airport. There are five routes from the airport bus to Xi 'an downtown, and the bus you choose goes to Xi 'an Railway Station (some buses are marked with destination signs on the front windshield). If there is no bidding, you can ask the driver to go to Xi 'an Railway Station, 27 yuan/person, which takes about 50 minutes from the airport to Xi 'an Railway Station).
After getting off, take bus No.20, No.28, No.213, No.519, No.712, No.718, No.719 and No.912 and get off at Colorful Mall. Or walk to Sanfuwan bus stop (just opposite the interchange). The departure time of Puyang is 19:30.