1. Iodine 131 therapy is one of the preferred treatments for adult Graves’ hyperthyroidism; 2. Iodine 131 therapy is particularly indicated in the following cases: 1) allergy or other adverse reactions to ATD (ATD includes methimazole and propylthiouracil); 2) poor ATD efficacy or multiple relapses; 3) contraindication to surgery or high risk of surgery; 4) history of neck surgery or external irradiation; 5) long duration of disease; 6) Elderly patients (especially those with high risk factors for cardiovascular disease); 7) combined with hepatic impairment; 8) combined with leukopenia or thrombocytopenia; 9) combined with heart disease; 3. Iodine 131 therapy is contraindicated in pregnant and lactating female patients, and caution should be exercised in women who plan to become pregnant within the next 6 months.