Among thyroid cancers, papillary carcinoma and follicular adenocarcinoma generally have a better prognosis; medullary carcinoma and undifferentiated carcinoma have a worse prognosis, and untimely treatment can lead to serious consequences, which is more terrible. Thyroid cancer can be divided into papillary carcinoma, follicular adenocarcinoma, medullary carcinoma and undifferentiated carcinoma. Papillary adenocarcinoma is the most common type of thyroid cancer, which is well differentiated and of low malignancy. Although lymph node metastasis and multicentric foci can be seen at early stage, the prognosis is generally better, with a 5-year survival rate of more than 90%, and most of the survival period is more than 15 years. Follicular adenocarcinoma has a moderate degree of malignancy, faster tumor growth, some vascular invasiveness, and a better prognosis, but not as good as papillary carcinoma. Papillary carcinoma and follicular adenocarcinoma are collectively referred to as differentiated thyroid carcinoma, which can be treated with radical surgery and iodine 131 radionuclide therapy with a high survival rate. Medullary carcinoma is of moderate malignancy, may have cervical lymph node and blood line metastasis, and its prognosis is not as good as that of follicular carcinoma, but better than that of undifferentiated carcinoma. Undifferentiated carcinoma of thyroid is highly malignant, with rapid progression and poor prognosis, and the one-year survival rate is only about 10%. Early active intervention may improve the prognosis, but without active treatment, the condition is mostly very serious. Regardless of the type of thyroid cancer diagnosed, one should consult the doctor in time and follow the doctor’s instructions for active treatment.