In order to improve the shipbuilding efficiency and optimise the shipyard segment manufacturing process, the Unity3D-based ship segment manufacturing simulation system is proposed based on the current situation of segment manufacturing in the shipbuilding industry. The functional features of the ship segment manufacturing simulation system are introduced in detail through segment model assembly, and the design and implementation of the segment manufacturing process are developed. Combining the purpose of the development and the object of use, the design ideas of the ship segment manufacturing simulation are discussed, the main functions of the system as well as the development platform and methods used are introduced in detail, and the design highlights of this system are summarised to provide a reference for the development of the ship segment manufacturing simulation.