Abstract: Cow's milk allergy is an immune-mediated response induced by the proteins found in cow's milk, which occurs early in human life and frequently affects the skin, respiratory system, and digestive system. It has now become the most common food allergy problem in infants and young children. If cow's milk allergy is not treated promptly, it will have an impact on infants' and young children's growth and development, and in severe cases, it may result in systemic anaphylactic shock or even death. Currently, probiotics have become an essential tool for treating cow's milk allergy; nevertheless, the mechanism by which probiotics regulate cow's milk allergy is somewhat complex, with no clear and precise conclusion. In this paper, the immune mechanism of cow's milk allergy, the relationship between gut microbiota and cow's milk allergy, and the mechanism of probiotics to alleviate cow's milk allergy in terms of gut flora regulation, intestinal barrier enhancement, intestinal mucosal immunity promotion, and cow's milk allergenic protein catabolism are reviewed. This study will help to explore the anti-allergic role of probiotics in gastrointestinal function and metabolism, with a view to providing new ideas for the prevention and treatment of food allergy.