In general, patients do not need to be hospitalized and can be treated on an outpatient basis. Usually the outpatient physician will choose the appropriate measures according to the actual situation and instruct the patient to prepare for iodine-131 treatment, which include: 1. Avoiding drugs and foods that affect the function of iodine-131 uptake by the thyroid gland, and the duration of prohibition depends on the drug or food. 2. Determination of thyroid iodine uptake rate and effective half-life, or thyroid scan, and routine physical examination with blood and urine routine, thyroid function, liver and kidney function and ECG examination if possible. 3. Estimate thyroid size and weight. 4.Symptomatic treatment for tachycardia and nervousness. 5.People with severe hyperthyroid symptoms may first use antithyroid drugs to control hypermetabolic symptoms 6.Advise precautions and sign the informed consent form.