The original urban planning can never meet the requirements of the rapid development and the increasing population in big cities in China. The best way to solve this problem is to develop the underground space (including tunnels). With the exhaustion and saturation of the shallow underground space, the development of urban area is more and more relying on the excavation of deep underground space. Nowadays, the advanced technology of high strength concrete, excavation method in soft soil and ground deformation control make it possible to build underground space with a larger scale, span length and depth. The common disasters and hazards that large urban underground space faces are the same as that of ordinary underground space, but considering the damage and the rescue difficulties, more attention should be paid to the influence of disasters on large underground space. The study and research on the evaluation of the disaster prevention system of underground space still have not raised enough attention yet. The Comprehensive Evaluation of the disaster prevention system is set up based on the study of the characteristics of large underground space itself and disaster effects. The evaluation of the prevention of fire, flood, earthquake and attack are discussed. This is a preliminary study of the future disaster management and emergency rescue of urban underground space.