In order to provide effective power for small aerocraft, this paper offers a design of an electromagnetic vibration energy harvester based on MEMS technology, which works in special launching environment. According to "mass-spring-damper" system theory, this paper firstly built a model of the pick-up system, and discussed the pick-up system's response to sinusoidal input and impact load. Then, an energy conversion system was modeled, in order to analyze the system's power output. ANSYS simulation has been done on the pick-up system of different structures & parameters, and the relationship between different structures & parameters and the energy harvester voltage output has been studied. Based on the theoretical analysis and software simulation, the designed energy harvester working high frequency vibration environment can produce voltage over 200mV, which is enough for micro-sensor, low-power circuit in aerocraft.