The survival time of thyroid cancer after surgery is related to the pathological type, surgical method and individual’s physical condition, and cannot be generalized. Thyroid cancer is divided into four categories: papillary thyroid cancer, follicular carcinoma, medullary carcinoma, and undifferentiated carcinoma. If patients with papillary thyroid cancer can tolerate surgery and can be removed cleanly, their 20-year survival rate can be over 90%. If the patient is inoperable or inoperable, the patient’s prognosis is usually poor and the survival time is reduced accordingly. In case of medullary carcinoma and undifferentiated carcinoma, the prognosis is usually relatively poor, especially for undifferentiated carcinoma, where the life expectancy is only 3-6 months after diagnosis and the one-year survival rate is only 5%-15%. Therefore, it is recommended that post-operative thyroid cancer patients should take thyroxine tablets for life as prescribed by their doctors, which can supplement thyroid function and inhibit the recurrence of thyroid cancer.