Abstract: A series of classified protection standards of cybersecurity, Classified Protection 2.0 for short, were released in 2019. Compared with the previous ones, Classified Protection 1.0 for short, Classified Protection 2.0 pays more attention to dynamic protection, integrated prevention and control and targeted defense. The challenges and requirements for railway network security are analyzed, the construction thoughts for the new technical system of railway network security under the guidance of Classified Protection 2.0 are given based on the current situation of railway network security. It is proposed that the new technical system be established based on security management center, secure communication network, secure zone boundary and secure computing environment. And the construction contents of security protection for emerging IT applications in railway are also proposed, offering reference for railway enterprises in the construction of technical systems of cyber security.