As the core technology to realize the information and digital transformation of the construction industry, BIM (building information modeling) technology has high research value in the whole life cycle of railway construction. In the design of railway communication equipment rooms, station yards, and intrastations, the spatial morphology of railway communication entity, such as spatial position, shape, size, and relationship, is described digitally. According to railway communication design specifications, relevant railway BIM standards, and professional design requirements, the digital engineering design system for railway communication is studied and developed. Supported by spatial morphological data and based on the decomposition standard of railway engineering entity structure, the system realizes the intelligent layout of indoor cabinet of railway communication equipment, the path planning of station communication trench cables, and the accurate layout of intrastation communication information points in a three-dimensional environment. Based on the digital engineering model and the basic principle of graph theory, the system obtains the logical relationship from the digital engineering model and generates the communication logical network diagram. Verified by the actual project, the system has greatly improved the design efficiency and accuracy of railway communication digital engineering, realized the delivery and application of digital achievements of railway communication engineering from the source of the project, and promoted the upgrading of technologies and innovation of digital modes in the whole life cycle of railway communication engineering project.