Multilayer micro nano films widely used in semiconductor, mechanical processing and other industries are usually formed by superposition of several single-layer films with nanometer thickness. Due to the limitations of process conditions in the manufacturing process, the film thickness may have uniformity errors, which will affect the performance of the films. Therefore, the accurate measurement of the film thickness is very important, and a nondestructive, high-precision and fast detection technology is urgently needed to measure and detect the thickness and uniformity of the film. This paper reviews the application status of multilayer films in different fields in recent years, analyzes the current technologies of multilayer thickness measurement, such as X-ray diffraction, and their shortcomings, and also reviews the research progress of ellipsometry. Finally, the application of machine learning in thickness measurement is introduced, and the prospect of the combination of machine learning and measurement in the future is discussed.