Abstract: With the fast development of computer technology,3D geological modeling has been paid more and more attention by geoscientists.Taking VII dam site of Xiangjiaba Hydropower Station as an example,some key problems and their solutions with 3D geological modeling were discussed:(1) Integration method of multi-format data was put forward;(2) Constructing method of geological curve surface based on Laplace interpolating points and original points was proposed;(3) 3D modeling method of approximately layered geological body based on cutting was summarized.At the same time,application of 3D model of Xiangjiaba Hydropower Station,that is,its display,auto plotting,VR flying and 3D numerical analysis etc.were illustrated.