Three-dimensional modeling for geology is one of the focused issues in geoscience community around the world. It abstracts geological results into geological models and realizes visualization analysis and management on computer. This paper illuminates the principle of the modeling method, data processing and visualization analysis, and integrates practice experiences of three-dimensional modeling in geology. Then some of the key technical issues involved in three-dimensional geological visualization, such as data fusion, mesh generation and virtual reality are discussed, and some specific examples are presented. This paper demonstrates that three-dimensional geological modeling can not only express more complex geological information efficiently, but also be applied to engineering practice.