Abstract: This paper proposed a network security monitoring, early warning, and disposal system based on asset mapping to address the problems of low risk management efficiency and delayed information transmission in the closed-loop disposal process of railway network security management, introduced the system architecture, functions, and specific processes are described, and key technologies such as port scanning, fingerprint recognition, and vulnerability scanning recognition, implemented rapid identification, assessment, and response to network security risks through the comprehensive use of asset management, risk management, and work order management functions. The system has been piloted and applied in China Railway Lanzhou Group Co. Ltd. The application results show that the system can implement closed-loop management of risk disposal processes, significantly improve risk disposal efficiency, effectively enhance network security management level, and provide reference for network security management of railway enterprises.