Abstract:As a popular open-source engine of 3D mapping, Cesium has been widely applied in various fields. However, the native Cesium does not have the ability for rendering the visualization of the underground pipe network model. A new modelling method was proposed for constructing 3D Tiles model automatically based on 2D vector data of underground pipe network. On the basis of the above operation, the visual display of the model was carried out. In the processes of modelling, the 2D vector data was graded and processed to quadtree structure. The point and line elements were used to generate a corresponding model transformation matrix by traversing the point and line elements. The relationships between the model transformation matrixes and its corresponding standard models were then established. The point elements were encapsulated as an i3dm model, and the line elements were encapsulated as a b3dm model afterwards. The 3D tiles underground pipe network model was finally obtained. The visual display of the model was realized by docking of data and model, setting the functions of surface transparency, hemline closing, and composition of the camera's underground perspective, which were based on secondary development of Cesium. The above model was tested and verified on the basis of the pipe network vector data of Beihai new area, which is located in Gaizhou, Liaoning province. The results show that 3D tiles model can be rapidly generated based on 2D underground pipe network vector data, and the underground 3D model can realize visualization display. It can provide technical support and method reference for the follow-up research on Cesium underground space. Furthermore, it can improve 3D underground visual management system of B/S structure, supporting the construction of digital twin cities.