Along with the development of terahertz(0.1-10 THz) spectroscopy, terahertz imaging has been applied in biomedical area, especially in skin burn detection. But how to transfer this technology from laboratory research to clinic application is still a great challenge. Terahertz technology has been studied in the area of skin burn severity assessment, including imaging system, ex-vivo experiments and in vivo experiments, and clear terahertz images can be obtained. In this paper, skin burn severity classification and diagnosis methods are reviewed, then focusing on the imaging system, detection results and burn severity assessment methods, the progress of terahertz detection of skin burn are introduced, and further explanation of its evaluation principle and shortages are analyzed. The status and problems of terahertz imaging, clinic application challenges are discussed in detail. Finally, the development tendency and problems to be solved of terahertz imaging on skin burn towards clinical application are proposed.