Food allergy is an abnormal or overpowering immune response caused by specific proteins. The current study of infancy is the age of susceptibility to food allergy, and in China infants aged 4-6 months are the high incidence age group, which may be related to the type of complementary foods added to infants and the immaturity of intestinal barrier function. more than 70% of allergic reactions in infants within 1 year of age are caused by food allergy. Food allergy is a systemic allergic disease, but its clinical manifestation is mainly based on gastrointestinal, skin and respiratory symptoms. Gastrointestinal symptoms include persistent diarrhea, vomiting, abdominal pain, blood in stool, etc. Skin manifestations are mainly eczema, urticaria, pruritus, erythema multiforme, etc. Respiratory symptoms include coughing and wheezing. The onset of the disease varies, and the severity of the disease varies, from sudden onset to death due to asphyxia or anaphylactic shock in severe cases. Common allergic foods include milk, eggs, peanuts, nuts, seafood, soybeans and certain fruits and vegetables, among which peanuts, nuts and seafood allergies are life-threatening for infants and children. It is well documented that children who suffer from food allergies during infancy are significantly shorter than their peers and have a higher chance of developing allergic rhinitis and asthma after early childhood than normal children. Treatment of food allergies can be reduced or avoided by proper dietary guidance. Therefore, timely consultation and proper diagnosis and treatment are very important.