A measurement error compensation method of straightening machine workpiece curvature based on support vector machine (SVM) was presented to solve the workpiece curvature measurement error of automatic straightening machine.In the process of test,the deflection detector was used to calibrate the workpiece curvature measured by straightening machine and the modeling data were obtained.During the modeling process,the optimized parameters of SVM were chosen by crossvalidation method.With these optimized parameters,the established model could be used to predict the workpiece curvature measurement error accurately.The SVM model was respectively used to predict the curvature measurement error of different workpiece and the same position.With the prediction results comparison,the compensation effect of SVM model is obvious.Therefore,it is valuable for engineering application.