how can i get from the airport to the south shaomen station?

You can take airport shuttle bus line 4, and get off at Xian Hotel. The operating hours are from 08:20 to 21:20. It takes around an hour on the way with the ticket fare of CNY 25 per adult.
After arrival, walk south along North Chang'an Road about 400 yards. Then you can see the metro station. :-)