Mega cities are highly populated centers of a vast of crucial social functions in a country. Emergency-medicine-reserve location (EMRL) in mega cities is one of the dominant factors for the efficiency of the emergency medicine supply, determining the security capability for citizen’s life and acting as an integral part of the national emergency support system. This paper explores the uniqueness of the emergency-medicine-reserve location in mega cities and constructs a new system of evaluation criteria from a new perspective with the coverage of demand, resource, policy, traffic, risk, etc. and proposes a model for location assessment based on ANP considering the interaction between different evaluation criteria. A case study of Beijing is carried out to generate the rank list of 10 areas of Beijing, indicating who has better potential to be a candidate point for emergency medicine reserve. Finally, some managerial insights are provided.