Right now, the lowest-price month to fly to Xian Xianyang is January/2020.
China Eastern fly direct between Australia and Xian Xianyang.
The cheapest airline that flies from Australia to Xian Xianyang is China Eastern.
The best airline to fly between Australia and Xian Xianyang is Singapore Airlines. If you want non-stop flights then China Eastern is best. AirAsia X is the best budget airline.