Abstract: The method of 3D solid modeling of irregular tetrahedron has many advantages, but the method can not accurately describe the layered interface in the layered ore modeling. According to the characteristics of the layered ore, the 3D solid modeling of irregular tetrahedral was established based on equidistance discrete contour. The logical model structure of this method formed point, face and tetrahedron. The method has been realized by programming with VC++.net. A 3D solid model of irregular tetrahedron has been established by actual data of a coal mine. Practice shows that the method can establish 3D solid model and accurately describe the ore body of the layered interface.