Abstract: In recent years, in order to ensure the safety of railway transportation, the displacement monitoring method of railway infrastructure using Beidou high-precision positioning technology has been widely studied. This paper introduced the principle of Beidou high-precision monitoring, expounded in detail the architecture, function and interface design of the railway infrastructure monitoring system based on Beidou positioning technology, and verified the function of the system through on-site monitoring data. The results show that the system can achieve millimeter level monitoring accuracy, and can provide technical support for railway infrastructure displacement monitoring.