Faced with the actual needs of rapid deployment and launching of small unmanned aerial vehicle(UAV), comprehensively considering the various launching forms and working conditions at present, a pneumatic module with constant power source pressure is constructed with pressure regulator and actuating value as the core,which improves the launching stability. At the same time, according to the characteristics of the pneumatic launching, based on the R-K gas equation of state, the physical model simplifying and the mathematical equation modeling of the launch process are performed, and the accuracy of the theory model is improved. Based on this, the functional relationship between the launching speed and time with the gas pressure and acceleration distance and other related parameters is obtained, which provides the basis for multi-domain expansion and detailed parameter design of the entire system.