Abstract: In view of the increasingly severe network security situation of railway key information infrastructure and the urgent need to optimize and improve the security protection system, this paper put forward a set of security protection framework with firm foundation and efficient measures, which had the function of consolidating the foundation of network security and improving the security protection ability of railway key information infrastructure. Practice shows that the proposed framework can improve the security defense capability of key information infrastructure, improve the performance of active defense and defense in depth, and provide theoretical and practical reference for further improving and optimizing the design and construction of railway key information infrastructure security protection system.