【Abstract】 The paper is on the representation of a cylindrical helix by NURBS curves. A method is given, which discusses the influence on the shape of helix, produced by different ways of determining the positions of their control vertexes. The error distribution cases between the helix approximated by NURBS curves and the original theoretical one are also analyzed, and in the meanwhile a computation method is pointed out, which guarantees the requirements of precision.更多还原