In accordance with the present situation and some problems in the area of 3D modeling, the technology of 3D modeling based on discrete algorithm was proposed. From the view of engineering application, this paper mainly discussed the data pre-processing of the 3D model face, the discretization of the 3D model face, topological relation based on the discretization meshwork model and mutual division algorithm of 3D model. Finally combining OpenGL,the Object ARX and Oriented Object Programming(OOP) technology, a simulation system of mineral deposit 3D model has been developed. The result shows that the 3D modeling method is much simple and practical, and has a wide area of application.