There is still a risk of recurrence after thyroid cancer surgery, especially for thyroid cancer that is locally advanced at the time of surgery or has already developed neck lymph node metastasis, in which case there is still a risk of post-surgical recurrence even after radical surgical resection of thyroid cancer and systematic lymph node dissection. Of course, advanced thyroid cancer refers to the occurrence of distant metastasis, such as lung metastasis, bone metastasis, liver metastasis, brain metastasis and so on. In this case, thyroid cancer is mainly treated with internal conservative treatment, or called anti-tumor angiogenesis treatment. For early thyroid cancer after surgery, if there is no residual, or if there is no lymph node metastasis, postoperative adjuvant treatment is mainly endocrine therapy of thyroxine supplementation, alternative therapy. It also depends on the specific pathological type of thyroid cancer after surgery, the degree of tumor load, and the degree of surgical clearance, etc., to make a comprehensive judgment on the means and modes of adjuvant treatment after thyroid cancer surgery.