Propylthiouracil is one of the thiourea class of antithyroid drugs, which is used to reduce the level of thyroid hormone in the blood by inhibiting the synthesis of thyroxine, thereby treating hyperthyroidism. The half-life of this product is relatively short, about 60 minutes. In addition, it has the effect of inhibiting the conversion of T4 to T3 in peripheral tissues, which can quickly control the symptoms of hyperthyroidism. However, because of the relatively short half-life, it is important to ensure that the drug is administered every 6-8 hours, and clinically, 2-3 oral doses of the drug are required daily. This drug is mainly used for the treatment of hyperthyroidism and thyroid crisis patients during T1 pregnancy, and its side effects are mainly damage to liver function and vasculitis. The side effects are mainly damage to liver function and vasculitis. Therefore, the medication must be administered under the guidance of a specialist, and should not be stopped or increased blindly, and should be reviewed regularly.