There is a straight flight between Tianjing and Xiahe.
From Xiahe airport, it is only 2.5h drivng to Langmusi.
From Jiuzhaigou airport to Langmusi is 4hour driving.

Buses in South Gansu

City1	City2	Departure Time	Travel Time	Cost RMB
Lanzhou	Xiahe	There are five buses at 7:30/8:30/9:30/14:00/15:00 everyday. Take this bus in The South Bus Station in Lanzhou.	4h	75
Lanzhou	Hezuo	Everyday from 7:00am to 4:30pm, there is one bus every 25 minutes	4h	75
Lanzhou	Diebu	There is three buses at 8:40am, 9:40am,10:20am.	9h	140
Lanzhou	Langmusi	There is no bus from Lanzhou direct to Langmusi. You can take the bus from Lanzhou to Diebu and get off at Langmusi Junction 4km out of the town.	7h	160
Hezuo	Langmusi	One at 6:30am.	3h	50
Langmusi	Hezuo	There is only one bus everyday at 7:20am.	3h	50
Langmusi	Lanzhou	There is no direct bus, please switch the bus in Hezuo. You can easliy make it in one day.	7h	160
Xiahe	Lanzhou	5 buses everyday at 6:30/7:30/8:30/12:10/14:55	4h	78
Hezuo	Lanzhou	Everyday from 7:00am to 4:30pm, there is one bus every 25 minutes	4h	78
Xining	Xiahe	There is one bus at 7:10am	6h	90
Xiahe	Xining	There is one bus at 6:10am	6h	90

Buses in Sichuan

City1	City2	Departure Time	Travel Time	Cost RMB
Langmusi	Zoige	Only one at 7:20am	2h	30
Zoige	Langmusi	One bus departs at 7am will pass by Langmusi around 9am. Another bus departs at 2:30pm straightly to Langmusi	2h	30
Jiuzhaigou	Chengdu	From 6:30am to 8am, there are several buses everyday	8h	158
Chengdu	Jiuzhaigou	From 6:30am to 8am, there are several buses everyday	8h	158
Chengdu	Zoige	Everyday one bus at 6:30am. In busy season will be one more bus at 7:00am. Take it in Chadianzi Bus Station.	10h	200
Zoige	Chengdu	Everyday one bus at 6:30am. In busy season will be one more bus at 7:00am.	10h	200