Abstract: Aiming at the problem of low power generation efficiency caused by fixed power generation mode, a design scheme of dual-axis photovoltaic tracking device based on 51 MCU is proposed, which takes STC89C52 as the control core, photosensor as the light seeking component and stepper motor as the driving component. The software and hardware design and key technical principles are analyzed and introduced. According to the direction of sunlight sensed by the photosensitive sensor, the stepper motor is controlled by an advanced algorithm to automatically and flexibly adjust the direction of the photovoltaic panel, so as to effectively improve the tracking accuracy and finally achieve the purpose of improving the photoelectric conversion efficiency.