Contact with children after iodine 131 treatment may be harmful, but there are no clear reports yet, and it is routinely recommended to avoid contact with children after treatment to avoid adverse consequences. Iodine 131 releases beta rays, which can destroy thyroid tissue, and patients who receive the treatment have a certain degree of radioactive contamination of the environment for a short period of time. The harm caused by contact with children after iodine 131 treatment has not been clearly reported, but because children are not yet fully developed and have high radiation sensitivity, it is routinely recommended that contact with them be avoided after treatment to avoid causing hypothyroidism, which may seriously affect the normal growth and development of children. Patients treated with Iodine 131 should avoid contact with pregnant women and children, and should consult their doctors for specific precautions.