In order to complete the conversion of environmental energy to electric energy,an energy conversion device using piezoelectric element to convert environmental energy is designed. The device uses a winddriven cantileverarm type pressuregenerating component to rotate while the piezoelectric plate is vibrated to generate electrical energy.Based on the basic theory of piezoelectric materials, the output model of the device is established,and the evolutionary algorithm based on the state space model is used to optimize the design of the device.The experimental test of the energy conversion device has been carried out. The experimental results show that the device can efficiently convert the environmental energy into the electrical energy.The design of this device provides a new method for the collection of clean environmental energy, and also points out the research prospects of the vibration energy harvesting device.