As the guidelines and legal basis of dealing with emergency events, the emergency capability of emergency plans, i.e. the degree of providing emergency knowledge affects the efficiency of emergency response directly. This paper proposes a method of evaluating emergency response capability of emergency plans based on matching of knowledge supply and demand. Through this method, the knowledge demand can be obtained via establishing the general process of emergency management and the hierarchies of emergency knowledge from the perspective of demand; the knowledge supply can be obtained via asking back emergency plans from the perspective of supply; emergency plans can be evaluated and diagnosed via the matching of knowledge supply-demand. With this method the emergency plans can be diagnosed to provide suggestions for revision and improvement.