At the hidden trouble of satellite station differential GPS positioning technology in the dynamic flight inspection of Fresnel lens optical landing aid system, a real-time relative positioning accuracy experiment based on Beidou movement is designed and carried out. Waypoint software is used for post difference data processing, and the post dynamic difference processing results are used as standard data to analyze and evaluate the real-time dynamic difference results of short baseline and medium long baseline from three aspects of heading angle, pitch angle and baseline length. The results show that the baseline accuracy is at the decimeter level, the heading angle accuracy is within 0.2°and the pitch angle accuracy is within 0.4°. It can be used as the comparison standard data in the dynamic to dynamic test scenario.