Abstract: In the study of CBM's drainage analysis and numerical simulation, 3D geological model of coal reservoirs structure is the starting point for numerical simulation and results analysis, which plays an important role. Three dimensional cuboids and other traditional grid can not express the changes of strata, but corner-point grid has the advantage of doing it. From the point of dynamic visualization of CBM, the paper established a 3D geological model of coal reservoir based on corner-point grid, studied the characteristics of data and the method to generate corner-point grids of CBM, developed a three dimensional visualization interface of coal reservoir using C# programming language combined with OpenGL graphic interface, expressed the coal reservoir geological structure in Panzhuang area, Qinshui basin, Shanxi Province with the model. The results show that corner-point grid is suitable for constructing 3D model of coal reservoir, which has a good expression of the structural characteristics of coal seam.