The Michelson interferometer is an important precision optical research instrument that uses the split-amplitude method to obtain coherent double beams to achieve interference. It has been in-vented since 1881 for nearly 140 years. However, in practical applications, there are still some differences in the understanding of the role of individual components, and there are some controversies about the concept of some interference in the light involved. Based on the principle and concept of the most basic light interference, this paper combines Young’s interference, equidistant interference, equal-thickness interference and Michelson’s interference for comparative analysis based on relevant literature data, and gives a reasonable viewpoint in order to calm down the existing disagreements and disputes.