With the rapid development of urban construction in our country, urban underground space informatization is increasingly valued by industry managers - underground space data is an indispensable and important part of urban construction, realizing three-dimensional informatization of underground space and building a three-dimensional city , providing scientific and technological support for the rational development of urban underground space resources, has become one of the most effective measures to solve urban problems. Therefore, studying high-efficiency, high-precision, and all-factor three-dimensional information acquisition and expression methods in underground space plays a crucial role in promoting urban construction and improving the level of urban informatization.