There are more than 3 000 kinds of volatile organic compounds (VOCs) in human exhaled gas, which are directly or indirectly related to the pathophysiological process of the body. Therefore, the detection and quantitative analysis of VOCs in vivo is helpful for the early detection, diagnosis and evaluation of treatment results. Breath analysis is a simple, noninvasive, painless, economic and time-saving detection method. It is a new field of rapid development, and has great potential in disease screening and clinical diagnosis. In this paper, the application of human exhaled gas analysis in clinical disease diagnosis and the latest progress in this field will be summarized.