Initiating explosive devices are the first component of the weapon system， their safety and reliability directly affect the safety and reliability of the weapon system. In order to meet the development requirements of miniaturization and integration of ammunition， the fuze is needed to integrate with initiator to form a micro-initiation system with high safety， high reliability， and multi-functional integration. MEMS （Micro-Electro-Mechanical System） safety and arming device （S&A device） is one of the key technologies. The development of MEMS S&A device used in micro-fuze and micro-initiation system in recent years was summarized， and the device material， device size， driven mechanisms， driven conditions， output efficiency， application platforms， and other aspects were compared and analyzed. Combined with the structure and size of the initiating device， the working principle of micro-initiation system with built-in MEMS S&A device was proposed. This MEMS initiator with built-in S&A device meets the development requirements of the next generation initiator， and it is also one of the main development directions of initiator in the future.