With the promotion of Engineering Procurement Construction mode in railway construction projects, collaborative management between design and construction has faced increasing challenges due to complexities of the participants and the various professional fields involved in railway EPC projects. This paper aims to analyze the issues present in the collaborative management of railway EPC project design and construction. Utilizing the social network analysis methodology combined with the Wuli–Shili–Renli (WSR) system methodology, a network model was established to explore relationships between design and construction management. This study investigates network-influencing factors and proposes targeted measures to enhance project management efficiency. The findings indicate that coordination and communication mechanisms, organization building, interface management systems and design management systems represent core network elements that significantly impact railway EPC collaborative management. These elements are closely related to other network factors. The research not only advances design and construction coordination theory, but it also introduces new ideas for engineering practice.