The main treatment for children with hypothyroidism is to give thyroid hormone replacement therapy. There are many reasons for hypothyroidism in childhood, most of them are due to primary hypothyroidism. In this case, different doses of eugenol should be given for replacement therapy according to the patient’s age and weight, and at different stages of the child’s growth and development. In addition, it is important to pay attention to whether this part of the child has a combination of other endocrine diseases. Since many children with hypothyroidism are combined with other endocrine gland problems, once the combination of other endocrine gland abnormalities is identified, it should be treated at the same time to prevent the lack or abnormal level of endocrine hormones from affecting the development of the child. Therefore, thyroid hormone replacement therapy can be given to hypothyroid children after the cause is identified.