Abstract: Cow's milk has rich nutrition and it is the best substitute for breast milk.However,its protein may cause allergy. The major allergen is casein,β- lactoglobulin and α- lactalbumin. This paper firstly illustrated the structure and epitope of cow's milk major allergen,and then discussed the effects of milk processing technology including heat treatment,fermentation and enzymatic hydrolysis on its allergenicity,and finally introduced the labeling and detection methods of allergen,which can provide reference for producing hypoallergenic dairy products.