The proportional pressure reducing valve used for automatic transmission gear shifting control was explored. Based on the structure and working principle, the mathematical models were established. The CAD model was built using Pro/E software, the multibody dynamics model was established by using the SimulationX. The static and dynamic characteristics of the valve were analyzed, the structure parameters were adjusted and optimized. The simulation results show that the principle and structural parameters of the valve are reasonable and meet the design requirement. The research provides references for the application of electrohydraulic proportional control technology in shift control.