The mathematical model of a certain aircraft cabin pneumatic pressure control system working in invariable control area was established, and the stability and dynamic characteristic of the system was simulated. The results show that the stability and dynamic characteristic of the cabin pneumatic pressure control system are good. The influence of the cabin cubage and the control cavity cubage on stability and dynamic characteristic of the cabin pneumatic pressure control were studied respectively. The research results provide reference for understanding the working principle, working course, stability and dynamic characteristics of cabin pneumatic pressure control system.