The artistic design of cruise ship interiors is getting more and more attention because of the gradual popularity of cruise travel. This article is different from the traditional interior design method. It uses virtual reality technology, takes the cabin of a domestic medium-sized cruise ship and a certain section of the engine room as the research object, and combines the Unity3D engine to develop a ship virtual roaming design and assembly system. In this way, it will explore the new model of "VR + ship interior + assembly". The system design serves conceptual design users and engineering construction users through virtual space display and interaction, with different functions. The system can not only enhance the design expression information of conceptual design users and improve the assembly design efficiency of engineering design users, but also multi-scene design with strong scalability and can be applied in multiple fields.