Abstract: In order to assist the operation department of urban rail transit to deal with traffic emergency, this paper studied and developed an assistant decision-making system for emergency response of urban rail transit traffic accidents.In case of traffic emergency, the system could quickly obtain accident information through automatic judgment or manual input of accident parameters, and automatically generated train operation plan adjustment scheme under traffic emergency, which provided reference for reasonable train turnover during traffic emergency; at the same time, the system would automatically predict the line network passenger flow under the traffic emergency according to the newly generated train operation adjustment scheme, and visually display the prediction results on the line network graph, provide data support for the line network passenger flow organization and facilitation during the traffic emergency, and implement the research goal of reducing the loss and impact caused by the traffic emergency.Taking Chengdu Metro Line 3 as an example, through the actual operation of the system, the functions of train operation plan adjustment and line network passenger flow prediction and display were verified.