A method of data processing applied to the measurement system of plate cam borderline is introduced in this paper, including the studies on fitting the sample data with cubic non-uniform B-spline curve based on least square method and radius compensation of the probe. 介绍了在平面凸轮轮廓线检测系统中所采用的数据处理方法,主要包括采样数据点的基于最小二乘法理论的三次非均匀B样条曲线拟合,以及补偿测头半径误差等方法的研究。