Abstract: With the rapid development of information technology, network security has become an important component of national security. As the main artery of transportation in China, the railway's critical information infrastructure is related to national security and economic security. It is not only an important protected object of the country, but also a key goal of network confrontation between countries. This paper combined the research and analysis of railway network security situation by the network security management department of railway public security organs in recent years, summarized the risks and hidden dangers of critical railway information infrastructure, and proposed network security protection measures from five dimensions.