Abstract: In this paper, an investigation was performed on the formation and correction method of the cross section curves of counter-rotating twin screws with two tips. The parametrical design and 3D modeling of counter-rotating twin screws were conducted by using SolidWorks API on the basis of this investigation. This program provided a useful tool for further finite element analysis and computer-aided simulation. This method makes 3D modeling easier for counter-rotating twin screws and thus enhances the operation efficiency.