In order to improve the oil pressure dynamic characteristics of the lock lubricating oil circuit of the heavy-duty hydraulic automatic transmission,based on the analysis of the working principle of the pressure regulating system,the simulation model of the lock lubricating hydraulic system was established by AMESim software.Simulation analysis of the dynamic characteristics of torque converter pressure regulating valve and lubrication pressure regulating valve were taken from different valve core mass,spring pretension force,spring stiffness and control cavity valve core diameter parameters.Finally,genetic algorithm was used to optimize the structural parameters which affected the dynamic characteristics of torque converter pressure regulating valve and lubrication pressure regulating valve.The optimization results show that the oil pressure fluctuation range of the optimized torque converter pressure regulating valve and the lubricating pressure regulating valve is significantly reduced in the process of pressure regulation,and the requiredtime to stabilize the oil pressure is also significantly reduced.