Abstract: In order to reach the rapid response requirement of the hydraulic retarder during vehicle braking process, the optimization of the hydraulic retarder control system was realized through two ways,increasing shunt structure in the hydraulic retarder control valve and adjusting the control signal of outlet throttle valve. To verify the performance of the optimized control system, the electro-hydraulic proportional pilot valve, the hydraulic retarder and the hydraulic retarder control valve before and after optimization were simulated jointly. The results about the inlet and outlet flow rate, the liquid-filled time of the hydraulic retarder, the inlet and outlet flow rate of the lubricant device of the gearbox, were acquired. The contrast analysis results show that, the response speed of the optimized hydraulic retarder is more rapid than that before optimization. And the optimized control system can increase the flow rate of shunt section and has no effect on the change trend of flow rate in other sections throughout the process cycle. The control method is suitable for the hydraulic retarder and it can also be used for other liquid components to reduce the response time.