This paper presents a new method for designing cross curve of counter -rotating twin-screw based on three degree quasi-uniform B-spline theory in view of free curve shape theory in CAGD.

• 本文从计算机辅助几何设计(CAGD)中的自由曲线造型理论出发，基于三次准均匀B样条理论提出了异向双螺杆端面曲线的设计新方法。