With the rapid growth of the number of registered locomotives in CMD system, a large amount of Beidou positioning data accumulated provides a necessary data foundation for generating orbital electronic maps with higher precision. However, the Beidou data sent by the locomotive will have a certain deviation, resulting in the displacement of the locomotive positioning or positioning as isolated points. In this study, the prediction equation was constructed by Kalman filtering algorithm to eliminate the outlier data in the Beidou data set, and the processed longitude and latitude data were further fitted with segmental curves, thus generating the electronic map of train track. The case analysis shows that using Kalman filtering algorithm and segmental curve fitting method to generate electronic map of Beidou positioning data can get close to real track line trend accurately.