According to the character of die shape, based on the mathematical model of multiple trimmed parametric surfaces, which is created by CAD/CAM system, an algorithm for generate mixed mesh of triangles and quadrilaterals for finite element analysis is presented. The trimmed parametric surfaces are discreted into polygons, which are controlled by the parameters of maximum edge length, minimum edge length, distance tolerance and angle tolerance, etc. The adjacent relation between surfaces is found and merged by surface-curves, consequently, a model represented by boundary is created, the polygons are updated by surface-curves, and mixed mesh is generated by these polygons. The resultant mesh is conformal, without crack and overlap between the adjacent surface.