There is no such thing as the best way to eliminate food allergy in a three year old child. Children’s food allergy can be eliminated by avoiding allergens, anti-allergy treatment, and desensitization. 1. Avoiding allergens: Food allergens can be determined by oral food excitation test and by combining with allergy history. The use of double-blind placebo-controlled food excitation test is the gold standard for the diagnosis of food allergy. After a clear diagnosis is made, these foods should be avoided in daily life. 2. Anti-allergy treatment: anti-allergy drugs can be used, such as cetirizine hydrochloride drops for oral treatment. In case of severe allergic reaction, adrenaline should be injected into the muscle as prescribed by the doctor. 3. Desensitization therapy: for example, if children are allergic to mites, at present, the main use of subcutaneous injection of dust mite allergenic dipping solution for desensitization therapy as prescribed by the doctor, after the beginning of the desensitization therapy, gradually increase the concentration of dust mite allergenic dipping solution, and when the highest therapeutic concentration is reached, enter into the stage of maintaining desensitization, at this time the amount of treatment is fixed. When a three-year-old child has a food allergy, it is recommended that he or she seeks medical attention in a timely manner so that the cause can be clarified with the help of a doctor and targeted treatment or therapy can be carried out.