轮廓测量是非球面光学镜面的重要测量手段，然而在测量过程中由于测量坐标系与理论坐标系间存在偏离，测量结果中存在误差.本文分析了离轴非球面的测量坐标系与理论坐标系间的平移和偏转误差在面形结果中引入的测量误差形式，根据最小二乘原理建立优化函数，依照函数特性通过数值差分法快速求解梯度并利用非线性优化方法优化偏差，从而将该误差从测量结果中剔除.仿真分析表明这种方法能在镜面面形残差和测量系统的随机误差的影响下有效恢复镜面面形信息.利用该方法实际指导直径为570 mm的离轴椭球面的加工，经过四个周期的测量-研磨过程使该镜面面形误差的PV值从34.80 μm收敛至13.83 μm，RMS从3.28 μm收敛至1.89 μm.为了进一步比较，对一块220 mm×96 mm矩形离轴椭球面测量，验证了该方法测量异形离轴镜面的适用性和通用性.

Profile measurement plays an important role in aspherical mirror testing. However, the coordinate deflection and shift will lead to errors in result. In this paper, the analytical mathematic formula for misalignment error is presented. The measurement results are optimized by numerical differentiation method and nonlinear optimization algorithm based on least square method and the influence of these errors is eliminated. This method can effectively reconstruct the off-axis aspherical surface with systematic error. After four times polishing of the 570 mm off-axis aspherical mirror, the surface PV and RMS are decreased from 34.80 μm to 13.83 μm, and from 3.28 μm to 1.89 μm, respectively. For further comparison, the 220 mm×96 mm off-axis rectangle-shaped mirror is measured and proved that this method has strong applicability and generality for special shape mirror.