According to the guidelines of the Chinese Medical Association Endocrinology Branch and Nuclear Medicine Branch on the diagnosis and treatment of thyroid diseases, the following nine types of hyperthyroidism are the best choice for iodine-131 treatment: 1. patients over 20 years of age with goiter II or higher; 2. contraindications such as failure of antithyroid drug therapy, allergy or leukopenia; 3. postoperative recurrence of hyperthyroidism; 4. hyperthyroid heart disease or heart disease with other causes; 5. 5. Hyperthyroidism with leukocytosis and/or thrombocytopenia; 6. Hyperthyroidism in old age; 7. Hyperthyroidism with diabetes mellitus; 8. Toxic multinodular goiter; 9. Functional autonomic thyroid nodules combined with hyperthyroidism. Iodine-131 therapy should be used with caution in the following patients with hyperthyroidism: 1. adolescents and children with hyperthyroidism who have failed treatment with ATD, refused surgery or have contraindications to surgery; 2. hyperthyroidism combined with impairment of liver, kidney and other organ functions; 3. infiltrative proptosis. Iodine-131 alone can be used to treat mild and stable moderate and severe infiltrative synostosis. For patients in progressive stage, prednisone can be added before iodine-131 treatment. Iodine-131 therapy is contraindicated in the following patients with hyperthyroidism: 1) women during pregnancy; 2) nursing mothers; 3) hyperthyroidism with extremely severe liver or kidney disease or myocardial infarction and other serious systemic diseases.