There are three main causes of hyperthyroidism liver function impairment: first, hyperthyroidism itself can lead to slight liver function impairment; second, liver function impairment caused by hyperthyroidism medication; third, liver function impairment caused by hyperthyroidism combined with other liver diseases. If the liver function damage is caused by hyperthyroidism itself, anti-hyperthyroidism medication or iodine 131 treatment can be given. As the thyroid function returns to normal, the liver function will generally return to normal gradually. If it is combined with other liver diseases, iodine 131 treatment should be used. If the liver function damage is caused by anti-hyperthyroid drugs, anti-hyperthyroid drugs should be stopped immediately and replaced by iodine 131 treatment; individual patients need to undergo surgery to cure the hyperthyroidism.