Abstract: Taking passenger flow scale, operation efficiency, operation safety and workload as primary indicators, an urban rail network operation situation evaluation indicator system comprising 20 secondary indicators is established. Operation situation early warning grades are divided, and the research idea of using Gradient Boosting Decision Tree algorithm to achieve a comprehensive evaluation of operation situation is proposed. Taking Chongqing rail transit network data as research object, by carrying out comprehensive assessment and verification of the operation situation early warning grades, the feasibility of the network operation situation comprehensive evaluation method is confirmed.