Since the combined effects of the rapid urban growth and climate change, disasters such as blizzard, hurricane, earthquake and traffic jar occur in nearly every city frequently. Building an urban adaptive emergency evaluation index system is a global topic concerned by experts in recent years. It is also a top priority in current urban planning. This paper makes comprehensive research and analysis on the urban adaptive emergency capacity. Firstly, it divides the city’s adaptive strength of disaster relief into tensile strength, bending strength, abrasion resistance, fatigue strength and breaking strength etc., which is the basic of building the integrated strength grade to evaluate the city’s capacity of keeping out incident. Secondly, it puts forward a set of scientific, complete and quantitative assessment index system (vulnerability, elasticity, stability, rationality and plasticity etc.) for emergency capacity which is based on the during-incident emergency evaluation theory, including Mitigability Measurement, Salvability Measurement, and Recoverability Measurement. Lastly, the paper studies the comprehensive evaluation index system of urban emergency capacity based on the external DEA, which can indicate the urban adaptive capacity of disaster relief in magic cube. Above all, the results can provide the reference for urban disaster risk management.