A general principle, a practical method and a modeling process of 3D visual model for complex geological entities contained faults are discussed. A kind of 3D vector data model, which is based on boundary representation, suited to geological objects and their topological relationships, is developed in order to organize and describe the 3D structure model of complex geologic body. A modeling approach called the unified modeling technique for stratum and fault is presented, and some actualizing techniques are discussed. To deduce and simulate the fault plane, three methods are presented based on the basic properties, characters and qualities of geological faults reflect on fault data. For the construction of stratum surface, the restriction and the shielding action of fault plane to the interpolation process of stratum surface are considered, and the mesh generation method for multivalued surface of reverse fault is developed. TRICUT, a method to clip triangle meshes, is used to process surface cutting on stratum surface and fault plane. A concrete example of using those methods to 3D bedrock model in the Beijing Olympic Green District is presented and confirms the practical result of those techniques.