Since 1817 scientists discovered trace element selenium, it has gradually clear that a variety of diseases has been in connection with selenium deficiency. Its relationship with the thyroid gland is gradually being known, this review focuses on selenium which plays an important role in the antioxidant system, immune system, deiodinase system, and to explore the mechanism of selenium to adjuvant therapy for hyperthyroidism, and provide a theoretical basis for the clinical study of hyperthyroidism treatment for radioactive 131I combined selenium elements.