The utilization of wireless sensor network has been limited on account of its disadvantages of traditional power supply. To make up for this, a micro power supply based on microscale piezoelectric has been designed, which can effectively pick up the vibration energy of surrounding environment, and then provide a steady stream of electricity for lowpower sensor system. The power supply is composed of the micro vibration generator based on microscale effect with external efficient peak of passive monitoring switch circuit, and the Matlab simulation analysis shows that the output voltage equals to 0.24 V. The passive peak monitoring switch circuit can guarantee all the charge output between the piezoelectric plates, and the output power of the proposed micro power supply is 3 times larger than that of the micro power supply with typical interface.