Abstract: To achieve intellectualization and miniaturization of fuze, a novel high-g dual-threshold MEMS (Micro-Electro-Mechanical Systems) inertial switch has been designed and simulated under the premise of ensuring its service safety and launching reliability. The MEMS inertial switch consists of two modules named recognition module M1 and energized module M2 respectively. It can recognize two typical loads (load 1: 15 000g-300 ms, load 2: 3000g-3 ms) by taking advantage of collisions between a mass and two baffles without power consumption. Planar Z-shaped tooth on the mass and two baffles are significant to recognize these two different loads and their parameters have been studied. Dynamic simulations have been taken to optimize the design. Corresponding simulation results show that when load 1 is applied on the switch in the sensing direction, it keeps disconnected, while load 2 is applied in the same direction, it is closed.