Comparing advantages and disadvantages of hydraulic transmission and pneumatic transmission, and combining the system index requirements, the pneumatic transmission system was selected as the research object. Due to the compressibility of gas, it is difficult for pneumatic transmission to realize slow action, the conventional method is to use simple exhaust throttling, the cylinder can produce obvious “crawling” phenomenon. The technology of charging back pressure and exhaust throttling was adopted in the adjustable speed pneumatic transmission circuit, the simulation model of high-pressure pneumatic damping exhaust was established by applying CFD technology, the damping characteristics were determined. The size of the exhaust damping hole is finally determined through the test, the low-speed “crawling” phenomenon is improved, the high-pressure pneumatic with slow and stable movement is realized. The adjustable speed dynamic system can realize fast and slow extension and fast and slow retraction of aircraft-missile launcher.