Abstract: Bioactive peptides become the focus of food research because of its wide source,easily digestion,absorption and use,highly safe,and many biological activities such as cholesterol reduction,blood pressure reduction,antibacterial activity,antioxidant activity and so on. However,the application of bioactive peptides in food is significantly affected by its structure and function,and its structure and function are closely related to the preparation,purification and structural identification of bioactive peptides. In this paper,the preparation,separation and purification and structure identification methods of bioactive peptides are introduced,and the principles,advantages and disadvantages of various methods as well as applicable objects are described. The structure-activity relationship and future development direction of bioactive peptides are analyzed,in order to provide new research ideas for screening safe and effective peptides,and provide theoretical basis for peptide application.