Tongue diagnosis is an important part of inspection diagnosis in traditional Chinese medicine. With the modernization of TCM tongue diagnosis, tongue diagnostic device has been widely used as a kind of important technical means in TCM tongue characterization in clinical research. This article is to summarize the development of tongue diagnostic device and the progress of its application in TCM tongue characterization over the past five years from integration of the disease and its TCM syndromes of integrated Chinese medicine and western medicine, TCM clinical effectiveness assessment and TCM health management, aiming at providing references for TCM tongue diagnostic characterization research.