Please take a look at the route from Dunhuang to Xining:

why do you want to go to liuyuan? For Yulin Cave? Now the train can go directly to dunhuang railway station, and the Yulin Cave is on the side. Going to Dunhuang instead of going to the western front is a bit of a loss. On the afternoon of the 2nd, you can stroll around the downtown area. The downtown area of Dunhuang is very small, so you can walk around Danghe River and see the Dunhuang Museum. Go to Shazhou Night Market in the evening. It is common to go to Zhangye on the 3rd, and the northwest train is late. Last year, I arrived at this train from Dunhuang to Zhangye at 16:35. As a result, the road was late and it was 18 o'clock in Zhangye, so don't plan according to the schedule. Danxia is more than an hour away from Zhangye city. I suggest you go there another day. In addition, it is a pity to go to Zhangye without going to horseshoe temple. The autumn colors in Zhuo'er Mountain are beautiful and worth seeing. As for Qinghai Lake, I suggest that you only take the eastern route. If you go there on October 1, there will be no green grass.