Among malignant tumors, the prognosis of thyroid cancer is generally good, and many thyroid cancers have metastases, but patients can still survive for more than 10 years. There are many factors involved in the prognosis, such as age, gender, pathological type, extent of lesion, metastasis and surgical procedure, among which the pathological type is the most important. In particular, papillary carcinomas tend to have good biological characteristics and have the best prognosis, but a few of them can also turn into undifferentiated carcinomas with very high malignancy, and undifferentiated carcinomas have the worst prognosis. The larger the size of the tumor, the more chances of infiltration, and the worse its prognosis. According to relevant statistical data, the presence or absence of lymph node metastasis K does not affect the survival rate of patients, but the uncontrolled primary tumor or local recurrence may lead to higher mortality rate, and the degree of direct tumor spread or infiltration is more important than lymph node metastasis.