Abstract: Based on the given full-length and short-turn routing condition, the traffic organization of Xi′an metro Line 3 is optimized. Aiming at the minimum passenger waiting time, the maximum average full-load rate of trains and the minimum vehicle total running distance, taking the departure frequency and train marshalling as the decision variables, a multi-objective optimization model of train plan is formed. The fminimax function in MATLAB software is used to solve the multi-objective nonlinear constrained optimization problems. The total passenger waiting time of during the morning rush hours remains unchanged, but the average full-load rate of trains is increased by 17%, and the total running distance of trains is reduced by 1 305 kilometers, resulting in the reduction of traction energy consumption by 3 027.6 kWh.