Milk and dairy product allergies are the most common food allergies in infants. In recent years， the prevalence of milk allergies has increased rapidly. Dairy product allergy refers to the immune response of a series of clinical symptoms caused by human ingestion of allergen ingredients， resulting in tissue or organ damage. Milk allergy seriously affects the quality of life of patients and their families， even more so than chronic childhood diseases. Although protein hydrolysates of different formulas are used clinically to replace cow milk， nutritional problems such as the bitterness of hydrolyzed protein infant formula powder and the slow growth of infants are still unresolved. At present， avoiding the use of cow milk and its products is a reliable solution to milk allergy. However， infants and children who do not consume milk protein can lead to malnutrition and slow growth. It is imminent to solve the problem of allergens in dairy products. Studies have reported fermentation and thermal processing， Physical processing （such as high-pressure dynamic micro-jet） and proteolysis are effective ways to desensitize. At present， the research on the function of probiotics is a hot spot in the food and medicine fields， and lactic acid bacteria fermentation may be an important trend and means. This article focuses on the research status of lactic acid bacteria fermentation to reduce milk protein allergies， summarizes the molecular characteristics of allergens in milk， allergy detection methods， etc.， explores the research methods of reducing allergenicity， and provides a certain reference for the research and development of hypoallergenic milk products.