[Objective] To discuss the cognition of the left-behind personnel in mountain area for geological hazard (such as collapse, landslide and debris flow) in order to evaluate local government's emergency management capability.[Methods] Xiaoyudong Town in Pengzhou City, Sichuan Province was selected as a study area, which is threatened by debris flow and other mountain hazards. Based on field survey data and descriptive analysis with SPSS and Microsoft Excel software, we got the recognition degree of interviewees for effective disaster prevention and mitigation measures.[Results] The left-behind personnel is limited in basic theoretical knowledge of disaster prevention and short of emergency response capacity. There are some mistakes and misunderstandings in public awareness of disaster prevention and mitigation. Through the existing evaluation model, the evaluation score, with respect to the ability of emergency management of Xiaoyudong Twon's geological disasters, is 84, which indicated that the regional emergency management ability is good, and the local people are more satisfied with it.[Conclusion] Before drafting an urgent plan, the government should fully consider the expectations of the left-behind group and the actual evacuation ability, rather than rely on the imagined situation to complete the planned work. At the same time, local government should strengthen the construction of emergency management capability and improve the coping ability of the sudden geological hazard.