In order to simulate the pressure load of the cabin cover in flight more accurately on the ground test bed, the controller design of the cabin pressurization system of the test bed is carried out by introducing the idea of piecewise control. According to the system structure of the cabin pressurization system of the test bed, the control system model is established, and then the PID closed-loop control of the cabin pressurization system is realized by piecewise control technology in the virtual instrument, so as to improve the applicability and stability of the system. The results show that the PID controller designed in this paper can improve the control accuracy and test efficiency of aircraft cabin pressurization system and meet the technical requirements of test bed pressure control system.