Abstract: To overcome the limits of traditional modeling methods using parallel and planar cross-sections,a new multi-body modeling method was put forward.The netlike cross-sections with the topological relationship of "node-arc-polygon" were utilized.The resulted models,without voids and overlapping,could also be smoothened all together.During the modeling process,the target area was subdivided into several cross-section grids,which could be modeled independently.All the sub-models in each grid were merged to build the final resulted models.Eight geological models in city geology survey were successfully constructed by using real data in Beijing,and the capacity of the method to quickly and exactly simulate large area with complex geological phenomena was demonstrated.