Keratin is a insoluble protein widely present in feathers and hair.Keratinase can catalyze the degradation of keratin and has great application value and potential in fields such as animal husbandry,leather processing,and medical treatment.In recent years,researchers have conducted extensive research on the source,classification,structure and function optimization of keratinase,and have achieved many results,providing a good foundation for the commercial application of keratinase.This paper reviews the research progress in the structure,function and application of keratinase,and proposes future research directions.