Aiming at the problem of low power generation efficiency of piezoelectric generator, an energy efficiency optimization system based on the microcomputer is designed. The energy efficiency of the device can be maximized through adjusting the cantilever beam length to change the natural frequency of the device and make the system adapt to the external vibration signal automatically. The rectification and transform can be carried out by using the LTC3331 power management chip, which not only can store the energy in the rechargeable battery, but also use part of the energy to support the entire system, and the optimization system can be selfpowered.