Abstract: Relocation of urban underground pipelines and space cmpitition are one of the main spatial conflicts in the planning and design of urban rail transit lines. Since the traditional 2D underground pipeline expression is difficult to directly express the disadvantages of the spatial position and space conflict of the pipelines, a combination method of visual segmentation and component model is adopted to solved the problem of three-dimensional automatic modeling of multi-type, different-diameter pipeline segments and connectors, based on the secondary development technology of Skyline 3DGIS platform. Then, a three-dimensional modeling method for underground pipelines suitable for the characteristics of long strip line is established, it achieves the intuitive 3D visualization of underground pipelines. By using 3DGIS spatial analysis technology, stereo buffer method and ray method, the spatial conflict analysis and the relocation calculation of underground pipelines are realized.