In view of the development requirements of miniaturization,large flow and high reliability of safety valve for missile gas circuit system,a new type of plunger structure safety valve was designed.The geometric model of the flow field of the safety valve was drawn,and the mathematical model of flow field was established based on Fluent.The detailed flow field analysis was carried out,the generation mechanism and influencing factors of safety valve cavitation were clarified,and the channel optimization method was put forward.The dynamic characteristics of the optimized plunger safety valve were analyzed by using AMESim software.Finally,the opening and overflow characteristics of the safety valve were tested by the test system.The test results meet the design requirements,the correctness of the theoretical analysis and design method is verified.