从迈克耳孙干涉仪干涉原理出发，分析了圆形镜面抛光面形误差对干涉调制度的影响。由于存在镜面面形误差，干涉调制度不能达到理想情况下的100%，但其干涉调制度不能低于理想情况下的90%。通过分析和讨论，镜面面形误差最好控制在λ/14 以内，干涉调制度才可能不低于90%，这样干涉仪才能保持比较满意的性能。同时，使用Zygo干涉仪对5组平面镜的平面度进行了测量，得到了这5组平面镜的峰-峰值和其他一些参数，通过分析测量结果，这5组平面镜的平面度都能达到干涉调制度的要求。通过对迈克耳孙干涉仪中平面镜面形误差的研究，这对于干涉光谱仪的设计、研制和性能的分析都具有一定的指导意义。

The effect on modulation depth caused by polish errors is analyzed from the interference principle of Michelson interferometer.The modulation depth cannot achieve ideally 100% due to surface errors, but the modulation depth cannot be below 90% in an ideal case. Through the analysis and discussion, it may be established that the surface errors should be plane to about λ/14 or better so that the modulation depth is not below 90% for satisfactory performance of the interferometer. At the same time, flatness for 5 mirrors is measured by Zygo interferometer so as to get peak to peak value and some other parameters.The flatness requirements of modulation depth is met according to the analysis of the measured results. Based on the study of the surface errors of the Michelson interferometer, it is a certain guiding significance to design, develop and analysis performance for an interference spectrometer.