A complex geological object is a 3D entities, owned many characteristics such as structural complexity, heterogeneity and anisotropy. Its geometric modeling expresses not only the external space form, but also internal property features. Through researching algorithms such as curved surfaces reconstruction, curved surfaces intersection, subdivision and suture, a triangulated irregular network (TIN) modeling of complex geological object face structure had been achieved. On the base of complex geological object face structure triangulation grid, using 3D limited Delaunay subdivision algorithm, a 3D solid modeling of complex geological object had been achieved to overcome the technology difficult of the complicated structure block modeling. It realizes the smooth interpolation of seismic imaging velocity depth block model using block body model and velocity control point.