Allergic conjunctivitis is the most common type of allergic eye disease, and the incidence in children and adolescents is increasing year by year. Drug therapy can only relieve some symptoms and only in a short period, while allergen immunotherapy is currently a therapy that can significantly improve the symptoms of chronic allergy and the course of the disease. This method has been used abroad for many years but has yet to be reported in China. The author reviews the effective mechanism and clinical efficiency of allergen immunotherapy and provides a reference for the further clinical application in China.