After returning from Lhasa and dropping off the train at Xining West, is there a bus I can take to go directly to Jiuzhaigou?

No, there is no direct bus from Xining to JZG. If you don't mind, it is suggested to take a direct plane to Chengdu and then transfer to another plane to JZG. Upon arrival, take a shuttle bus to the valley within around 1.5h.

Or you can take a train from Xining West to Lanzhou. Then go to Lanzhou East Bus Station to take the only bus to JZG directly and the bus starts at around 08:00 in the morning and lasted about 8 to 10 hours on the road.

For the exact departure time, it is suggested to confirm at East Bus Station again one day before your journey.