Heliox is a mixture of helium and oxygen in a certain proportion. Traditionally, it is mainly used as respiratory gas in deep diving operations. In recent years, heliox has been used in the prevention and treatment of respiratory diseases, ischemic diseases, and decompression sickness because it can reduce respiratory resistance, increase tissue oxygen content, and inhibit inflammatory response. In the future, with in-depth study of heliox, its application will continue to widen. This article systematically introduces the application of heliox in medical practice from 4 aspects: physical and chemical properties, disease prevention and treatment, treatment methods, and risk control, hoping to provide a reference for further research.