In order to improve the response performance and environmental stability of wind turbine yaw hydraulic brake system，a new type of brake with pressure control function was improved on the basis of conventional yaw brake.Taking 2 MW and 8 MW wind turbines as examples，the main methods and beneficial effects of the pressure-controlled yaw brake used in design of yaw hydraulic brake system were expounded，and the simulation analysis and comparison of full pressure braking and damping braking conditions were carried out for yaw hydraulic braking system with and without the brake.The results show that pressure-controlled yaw brake can significantly improve the response speed and low temperature stability of braking system.The study provides a reference for optimal design of wind turbine yaw brake and yaw hydraulic brake system.