Dêqên occupies the northwest corner of Diqing Prefecture, and in latitude has a range of 27° 33'−29° 15' N and in longitude has a range of 98° 36'−99° 33' E, covering an area of , bordering the Tibet Autonomous Region to the northwest and Sichuan to the northeast. It is located in the central part of the Hengduan Mountains, and contains the valleys of the Salween, Mekong, and Jinsha Rivers.