Dunhuang has a small airport (DNH) with daily flights from Lanzhou and Xi'an, and seasonal services from Beijing, Shanghai, Xi'an and other major cities — by far the easiest way to arrive if you're short on time.
The overland alternative is the train. Dunhuang station, called Dunhuang Railway Station, is about 13 km east of town and is served by both regular sleeper trains and the newer high-speed line through Liuyuan. Coming from Xi'an the high-speed train takes around eight hours; from Lanzhou about five. A second station, Liuyuan South, sits 130 km north of Dunhuang on the main Lanzhou-Urumqi line and is connected to town by a 90-minute shuttle bus — slightly faster overall for some routes.
A long-distance bus station in the centre of town has services up and down the Hexi Corridor: Jiayuguan (5 hours), Zhangye (8 hours), Hami in Xinjiang (6 hours) and onwards.