is it has been provided bus shuttle front international xian xianyang airport to linxia?

No, there is no long-distance bus at the airport that can take you to Linxia directly. You need to take shuttle bus line 3 to Railway Station first. Then take a train to Lanzhou first. Then take a taxi to Lanzhou South Bus Station. Many direct buses to Linxia are scheduled there from 07:00 to 19:40 every 10-15min.