Abstract: With the rapid development of the information field, our needs for information perception and processing technology are becoming more and more diverse. In order to meet the functional needs while reducing system cost and complexity, multi-functional integrated information perception and processing technology becomes more and more important in the field of civil and national defense. As a kind of optical fiber that can transmit multiple modes at the same time, multimode fiber was mainly used in the field of short-distance optical communication in the early days. In recent years, with the development of research on its complex physical properties, multi-mode fiber has been widely used in measurement, optical computing and image transmission due to its advantages of broadband, passive, easy to manufacture, low cost and portability. In this paper, the research status of the application of multi-mode fiber in spectral analysis, RF spectrum sensing and imaging technology are reviewed from the aspects of technical background and principle. The advantages of multi-mode fiber over traditional methods are expounded, and the challenges and future development trends of multi-mode fiber for these special fields and integrated applications are pointed out.