In order to reduce the fuel consumption rate of the engine and improve the efficiency of the transmission system, the optimal power shift path is calculated. The dynamic model of engineering vehicle transmission system is established and the dynamic shift strategy is simulated. The simulation shows that the optimal dynamic shift strategy can improve the acceleration and dynamic performance of the vehicle and greatly improve the shift quality of the vehicle. Improve the fuel economy of engineering vehicles, so that the overall energy saving effect of the whole machine is better. The test results show that the speed change of gearbox before and after the shift is relatively gentle, indicating that the new dynamic shift strategy can reduce the gearbox shift time, and the dynamic response of the gearbox is effectively improved during the operation of the engineering vehicle. It shows that the improved BP neural network control method can effectively control vehicle automatic shift. The research results have important theoretical and practical significance for improving the dynamics, economy and intelligence of engineering vehicles.