The Milin County along Yarlungzangbo River is closed to the Indian Plate with the Eurasian Plate collision zones. This paper uses the remote sensing and field investigation and examines 34 debris flow gullies which have an integrated deposit fan. Based on the found single factor regular, the predicting model on evaluating the debris flow’s hazardous range is established. This model absorbs the previous model advantages, distinguishes the risk range by less factors and saves time. It can be better and faster against the disaster.