The pilot type pressure reducing valve is widely used in the high pressure pneumatic and hydraulic systems. Due to its static and dynamic characteristics have a significant effect on the working condition of the entire loop, the work characteristics of pressure reducing valve should be analyzed. For a pilot type pressure reducing valve with typical structure, its mathematical model and simulation model were established; based on the simulation results，the output pressure and flow rate and other static and dynamic characteristics were analyzed, so the working status and internal mechanism of pressure reducing valve could be understood better. It is shown the AMESim simulation has such advantages of simple modeling, accurate model, fast operation, lower test and design cost.