在移相干涉中，由于系统或者环境的原因会产生移相误差，进而导致面形检测产生误差。介绍了最小二乘迭代随机移相算法的基本原理，通过模拟仿真，高精度地迭代出原始面形。针对随机移相可能引起迭代得到的面形与真实面形相反的现象，理论上分析了其产生的原因。提出在最小二乘迭代随机移相算法中，需要已知移相方向才能准确迭代出真实面形，通过实验进一步证实结论的正确性。给出了干涉仪移相方向标定的可行方法。

In phase shifting interferometry, surface measurement error will exist due to the phase shifting error resulted from the system or environment. The principle of the least-squares iterative algorithm with randomly phase shifting is introduced. The original surface can be reconstructed with high accuracy by iteration in the numerical simulation. The phenomenon that the reconstructed surface may be inversed to the actual one because of the randomly phase shifting is analyzed. It is proposed that the phase shifting orientation should be known in this algorithm to achieve correct results. Experiments are carried out for verification. The calibration method of the phase shifting direction of the interferometer is indicated.