The pneumatic launch technology has been widely concerned and applied in in UAV take-off and other fields of weapon launching. This paper summarizes the theoretical research and engineering applications of the pneumatic ejection system. The related theoretical research progress, the research and development of the key technologies, and the development status of catapult products are discussed. In the research on the multi-refrigerant pneumatic system, it is found that compressed air launch is the majority, but the pneumatic catapult with compressed carbon dioxide as the working medium has higher performance. However, it will be limited by the triple point temperature of carbon dioxide under some operating conditions, and thus needs to be further studied to improve the comprehensive performance of the system. In the research on the basic theory of interior ballistics of the ejection system, the research methods are various, and the theoretical methods are more mature. However, in practical engineering application, both the system performance and the lightweight of equipment need to be taken into account, considering the ejection requirements for high quality and speed. Thus, it is difficult to design the ejection system, and structural design optimization for practical application needs to be further strengthened.