Iodine-131 treatment is commonly used in clinical treatment of hyperthyroidism, thyroid malignant tumor postoperative adjuvant therapy, generally speaking, the following precautions are often made after iodine-131 treatment: First, iodine-131 treatment can be eaten at least 2 hours after treatment, treatment of the same day, it is recommended that the patient drink more water to promote the excretion of iodine in the body; Second, the patient should maintain a good state of mind in the 2-3 weeks after the treatment, strengthen the nutrition, and avoid excessive exertion. Avoid overwork, and do not contact with infants, young children, pregnant women for a long time; Third, do not eat foods with high iodine content, such as kelp, seaweed, seafood, for at least 1 month after iodine-131 treatment, so as not to affect the effect of iodine; Fourth, patients can be examined for thyroid function every month, and reviewed for 3-6 consecutive months, to observe the effect of the treatment and the recovery of patient’s condition, and the patients who are dissatisfied with the effect of iodine-131 treatment should be given more drinks to promote the excretion of iodine. For patients who are not satisfied with the effect of Iodine-131 treatment, the second treatment can be carried out.