Abstract: This paper proposed a station yard digitization system based on Beidou System positioning technology. An accurate location information was obtained by using RTK differential positioning technique, transmitted to host computer by wireless mode. The upper computer processed the location information, call the station yard map to match the location information with the physical element, and implement the station yard digitization, store the station yard map of matching the location information. After testing, the positioning accuracy of the system was within 10 cm. C++ builder was used to develop upper computer software under Windows platform. C language was used to develop embedded software under KEIL platform. The system has the characteristics of accurate positioning, convenient operation, high expansibility and high reliability, provides reliable guarantee for train safety protection, dispatching and monitoring.