偏振光干涉实验是大学物理实验教学中重要的组成部分.本文基于马赫-曾德尔光路，自主搭建光路观察偏振光的干涉现象，量光强变化，判断偏振光的偏振形态，测量实验室环境下的空气折射率.并在此基础上完成了数据处理和误差分析，根据实验数据可知，本实验的误差均在5％以内.改进后的实验装置不仅原理清晰直观，还可以通过添加某种光学元件进行拓展应用，提高了大学物理实验教学的效率，调动了学生参与实验的积极性.

Interference experiment of polarized light is important in college physics experiment teaching. Based on Mach-Zehnder optical path, a self-built optical path is improved to observe the interference phenomenon of polarized light, to measure the change of light intensity, to judge the polarization form of polarized light, to calculate the refractive index of air in the laboratory environment. Data processing and error analysis are completed to having an error within 5%. Compared with the traditional experimental teaching method, the improved experimental device not only has clear and intuitive principle, but also can be expanded and applied by adding some optical components, so as to improve the efficiency of college physics experiment teaching and mobilize the enthusiasm of students to participate in experiments.