This paper introduces a rapid modeling method of 3D geological model for subway construction, which is convenient for construction companies in engineering of urban rail transit projects. By using the software platform of AECOsim Building Designer, a 3D geological model is finally established based on the map of geological cross section, through inserting control points, fitting geological interfaces and linking geological attributes. The modeling progress is easy, and the data are all of daily use for the construction companies, to satisfy the everyday application in construction engineering. The visualization of 3D geography and results of data query are able to create more real and intuitive understanding on various geological structures for the site technicians and managers, as well as to assist in solving different geological construction problems.