Abstract: According to the grade spatial distribution of regular volume data from interpolation, the deposit volume data was divided into several sections. The 3D Delaunay algorithm was adopted to separate the 3D point set in each section and to extract the surface of those points, and the local model based on irregular tetrahedral was built up. All of the local models were composed by OpenGL's blend technique to achieve the simulation process of deposit. The idea of "the part model building, the conformity displays" was used to resolve the contradiction between rendering speed and detailed expression and give out the method of mineral reserve computation. The model analyzed with OOA constructs the data structure of base class, and has well aoolications and expansibility.