Abstract: This paper proposed a distributed Agent based network space resource mapping management system to address the complex topology and difficulties in cross network segment detection in the railway industry's network space surveying and mapping. The paper addressed the technical challenges of cross network segment mapping through asset identification, terminal information collection, and automated network topology construction, and significantly improved scanning efficiency and asset coverage through multi-threaded asset detection, customized fingerprint recognition, and a topology optimization model based on Dijkstra's algorithm, provided reliable technical support for network security in the railway industry.