///In recent years, “Valley-Gully Domain Economy” is the new development mode for the mountainous area in Beijing City. Miyun is a place of picturesque and beautiful scenery that has the good tourism conditions. The authors survey geological disasters of debris flow in the Simatai-Wulingshan Valley-gully Economic Domain, analyze the geology, topography and rains and so on, summarize the development and distribution characteristics of the debris flow, and put forward the corresponding prevention and control measures.