Research was carried out on the pure electric sport utility vehicle (SUV) transmission system coupled with 6-speed dual clutch transmission (DCT). Based on AVL Cruise software, the car is modeled, and the software simulation results meet the constraints. To further improve the performance, it is equipped with the joint simulation model of Isight and Cruise, adopts non-dominated sorted genetic algorithm II (NSGA-II), takes the transmission ratio of the pure electric SUV transmission system as the optimization parameter, the NEDC cycle The power consumption per 100 kilometers and the acceleration time to 100 kilometers under working conditions are optimized by multi-objective optimization calculations. The optimization results are entered into cruise software for review, and the outcome shows that, compared with before optimization, the power consumption per 100 kilometers of the NEDC cycle is reduced by 1.39kWh, and the economy is improved by 11.02%; the acceleration time to 100km/h is reduced by 0.81s, and the dynamic performance is increased by 7.03%