A new method, obtaining the pressure-time relations during air inflation and deflation process, is proposed to research the dynamic characteristic of a pneumatic solenoid valve. The current, magnetism, mechanical and air subsystems of the valve are investigated. In order to experimentally verify the advantage of the new model, two models are compared. Simulation results show, the opening and closing reversal times of the model without air subsystem are 29.6ms and 30.7ms. The new model’s reversal times are 31.8ms and 36.1ms. 32.5ms and 35.3ms are the results by experiments. The experimental results show very good agreement with the new model.