Treatment of low thyroid hormone is as follows: 1. The thyroid gland itself is diseased, due to hyperthyroidism and low thyroid stimulating hormone, which needs to be treated accordingly, i.e. the application of anti-hyperthyroid drugs, such as methimazole and propylthiouracil, etc.; 2. The lesion caused by hypopituitarism, resulting in a decrease in the level of hormones secreted by the thyroid gland, can be treated with thyroid hormone supplementation or levothyroxine sodium tablets. Hypothyroidism caused by pituitary inflammation can be improved by supplementation with levothyroxine sodium tablets or thyroid tablets.