Cavity enhanced absorption spectroscopy (CEAS) technology is an important part of high sensitive spectroscopy, which has the advanced characteristics of relatively simple apparatus, high sensitivity, and strong environmental adaptability. With the development of semiconductor materials and packaging technology, CEAS has been greatly improved in the light path structure, light source selection, and combined application with other spectral technologies. It has been widely used in the fields of environmental monitoring, medical diagnosis, national defense construction, industrial production, and other fields. The research status, development trend, and application fields of CEAS are discussed in detail. Starting from the CEAS basic physical principles, we describe the common experimental configurations based on different light sources, and analyze the improvement of system performance by improving the geometrical structure of the optical path. In addition, the present combined application of CEAS with other technologies in different fields is summarized. Finally, the future developments of each CEAS device are prospected.