To meet the development requirements of miniaturization and high reliability of weapon and ammunition safety system, a safe and arming device of pyrotechnical micro-electro-mechanical system(PyroMEMS) based on silicon double solid beams was designed. The compressive strength and overload strength of the solid beam in the safe and arming mechanism layer were simulated by using ABAQUS software. The principle prototype of safe and arming device of PyroMEMS was fabricated using micro-electro-mechanical system(MEMS) technology according to the simulation results. In order to study its actuation performance, the Si/Pb₃O₄ mixture of mass ratio as 1:9 was selected as ignition powder and the C₆H₂(NO₂)₃OK/KClO₄ mixture of mass ratio as 1:1 was selected as gas generator. Results show that the compressive strength is 310.03 MPa and the overload strength is 47.31 g as the boh length size and width size of silicon double solid beams in the safe and arming device are 300 μm.The designed PyroMEMS S & A device can successfully realize safe and arming functions.