Abstract: This paper studied the overall ideas and implementation strategies for the unification of railway information systems, in response to many challenges such as scattered development, multiple development entities, and difficulties in operation and maintenance, analyzed the current situation of railway information system construction and proposed specific requirements for the unification of railway information systems. Based on the application modernization theory, the paper proposed a general idea for the unification of railway information systems, and put forward specific implementation plans from the management level, technical level, and business level. Among them, at the business level, three methods were proposed: universal standardization, series standardization, and modular standardization. The paper planed a unification implementation strategy for the next 3-5 years and proposed safeguard measures. The research results can provide systematic theoretical references and technical support for the unification of railway information systems.