The main action of CNC fully hydraulic die forging hammer is controlled by blow hydraulic valves, which also directly affect the performance of forging hammer with its dynamic performance. The hydraulic system of CNC fully hydraulic die forging hammer was simulated and analyzed by using the software SimulationX, and performance curves and the related parameters were obtained and compared with the actual situation. As the result, the operating parameters of blow hydraulic valve are obtained, which lay the foundation for its structure design and optimization. 