Acceleration sensor can monitor acceleration and trigger switches i n a dynamic environment. Based on the coupling mechanism of magneto-mechanical, this paper presents the design of an acceleration sensor . With the characteristics of integrated mechanism of perception and triggering, no power consumption and high robustness, it can be widely used in active and passive vehicle safety, robot and dynamic monitoring system. In order to improve the robustness of system, the closing and holding mechanism of switch is designed. Considering the comprehensive effects of elastic element, suction contact and permanent magnet, the paper built the mathematical model of sensor and the threshold searching algorithm. The simulation results show that the acceleration switch has the characteristic of sensitivity in specific dynamic signal, and it works well in overload and vibration disturbance environment. In conclusion, the paper presents a new design model and method for bilateral multi- stage acceleration sensor.