Thyroid cancer is divided into: papillary carcinoma, follicular carcinoma, undifferentiated carcinoma, and medullary carcinoma. The first two types are differentiated thyroid carcinoma, which account for 90% of the cases and have good prognosis. The latter two types are rare and have poor prognosis, especially undifferentiated carcinoma, which has a very poor prognosis. Different types of thyroid cancer have different treatment methods. The treatment of thyroid cancer includes surgery, thyroid hormone therapy, radionuclide therapy and external radiation therapy. Surgery Surgery is the basic treatment for all types of thyroid cancer except undifferentiated carcinoma. It includes surgery of the thyroid gland itself and cervical lymph node dissection. According to the “Guidelines for the diagnosis and treatment of thyroid nodules and differentiated thyroid cancer” in September 2012, total/near-total thyroidectomy or thyroid lobectomy + isthmus should be selectively applied to differentiated thyroid cancer, including papillary carcinoma and follicular carcinoma. According to the 2012 US NCCN guidelines, total thyroidectomy should be performed for medullary thyroid cancer. Most undifferentiated thyroid cancers cannot be removed surgically when detected. 2. Cervical lymph node dissection: (1) With effective preservation of the parathyroid glands and the laryngeal nerve, lymph node dissection in the ipsilateral central region of the lesion should be performed. (2) For patients with DTC who have non-central lymph node metastasis in the clinical neck, lymph node dissection in the lateral neck area is performed. (3) Selective cervical lymph node dissection should be performed in some patients with clinical central cervical lymph node metastasis. Postoperative AJCCTNM staging and low, intermediate and high risk of recurrence stratification should be performed for all DTC patients to help predict patient prognosis, guide individualized postoperative treatment and follow-up protocols, and exchange patient medical information. Thyroid hormone therapy Thyroid hormone therapy should be administered after surgery for differentiated thyroid cancer. Radionuclide therapy 131I is one of the important means of postoperative treatment for DTC. 131I therapy consists of two levels: firstly, 131I is used to remove residual thyroid tissue after DTC surgery, referred to as 131I nail clearance; secondly, 131I is used to remove metastases of DTC that cannot be removed by surgery, referred to as 131I focal clearance. External radiation therapy is mainly used for undifferentiated thyroid cancer and differentiated thyroid cancer that is partially unresectable and radioiodine treatment is ineffective.