What is the fastest or most efficient way to get from Deqin back to Kunming?

You may take a bus to Shangri-la from Deqin Bus Station. The trip takes about 4 hours. The fare is about CNY 58. Upon arrival, take a taxi to the airport for about CNY 25. Then, take a flight to KM (about 1 hour).

Or, you can take a direct bus to KM from Deqin Bus Station. The bus departs at 13:00. The fare is CNY 258. The trip takes about 12 to 13 hours. :)