本文给出了基于数控加工的三次B啨ｚｉｅｒ曲线变步长直线插补算法 ,和算法在程序上的实现。即在德卡斯特里奥算法和细化的基础上 ,引进B啨ｚｉｅｒ曲线起点切矢与Ｘ轴夹角λ这个参数 ,通过控制相邻两段B啨ｚｉｅｒ曲线起始切矢与Ｘ轴夹角λ的夹角差△λ在恒定范围内 ,对德氏点进行取舍 ,从而得到一组适合于数控加工的B啨ｚｉｅｒ曲线插补点。 In this paper, a cubic B 啨 zier curve variable step linear interpolation algorithm based on NC machining is given, and the algorithm is implemented in the program. That is to say, on the basis of the de Castro algorithm and the refinement, we introduce the parameter λ, which is the angle between the tangent vector of the B 啨 zier curve and the X axis. By controlling the initial tangent vector of the B 啨 zier curve between two adjacent segments and the X axis Angle between the included angle λ △ λ within a constant range, the Derwent points were chosen, resulting in a group of B 啨 zier curve interpolation point suitable for CNC machining.