There are no known adverse effects of exposure to children after iodine-131 treatment, but because of their underdevelopment and high radiosensitivity, it is routinely recommended that contact with them be avoided after treatment in order to avoid adverse effects. Iodine-131 therapy, also known as radioactive iodine therapy, is a treatment administered by oral administration of the artificial radionuclide iodine-131. Iodine-131 treatment mainly utilizes the iodine uptake capacity of the thyroid gland and the destructive effect of iodine-131 rays on the follicular epithelial cells of the thyroid gland, so as to achieve the purpose of treating hyperthyroidism and thyroid cancer, and it is a precise and targeted treatment. Iodine-131 releases short-range beta rays, so it mainly plays a killing role in the thyroid tissue, with less damage to other tissues of the human body, and is relatively safe. Although there is no clear report on the adverse effects of exposure to children after iodine-131 treatment, it is routinely recommended to avoid contact with children and pregnant women who are highly sensitive to radiation after treatment because of the radioactive contamination of the surrounding environment after iodine-131 treatment, in order to avoid adverse consequences.