Postoperative thyroid function follow-up is consistent with DTC, but does not require TSH suppression therapy. Serum calcitonin and CEA are the more specific biochemical indicators of MTC and are mandatory for follow-up review. For patients whose serum calcitonin and CEA levels return to normal after surgery, the follow-up period can be referred to that of low-risk DTC; for patients whose serum calcitonin and CEA have not fallen to the normal range but are at lower levels, the follow-up period can be referred to that of high-risk DTC; for patients whose biochemical indexes are still at high levels, close follow-up should be performed, and it is recommended to review ultrasound in 3-6 months, and to combine with CT or MRI to determine the extent of the tumor according to the magnitude of the increase in serum calcitonin and CEA. It is recommended that patients with high level of biochemical indexes should be followed up closely.