This paper showed that interleukin-17 (IL-17) and its family members play a significant role in allergic reactions. The differentiation and regulation of IL-17 in allergic reactions and its mechanism, as well as the research progress in autoimmune diseases, parasitic infections, asthma, hydatid diseases and other diseases were reviewed. The mechanism of IL-17 promoting inflammatory response in different allergic diseases was analyzed. At present, there has been breakthroughs in the application of IL-17 in targeted therapy. Also, IL-17 antibody has been applied in the treatment of some allergic diseases. This paper also analyzed and predicted the application prospect of IL-17 antibody in the future.