Thyroid with lymph node metastasis may not be treated with iodine 131 if it is a differentiated thyroid cancer with low risk of recurrence, and is recommended for the rest. Thyroid cancer can be classified into papillary, follicular, medullary and undifferentiated carcinomas. Papillary and follicular adenocarcinomas are collectively referred to as differentiated thyroid cancer. Differentiated thyroid cancer retains some iodine uptake capacity and is better treated with iodine 131 radionuclide therapy; medullary carcinoma and undifferentiated carcinoma patients have poorer results with iodine 131 therapy. Patients with differentiated thyroid cancer can be stratified for risk of recurrence. Patients who meet the conditions of combined small amount of lymph node metastasis (i.e., no lymph node metastasis on clinical examination and ≤5 microscopic metastatic lymph nodes on pathological examination), as well as those who have no distant metastasis, have not invaded the surrounding tissues, and the tumor tissues visible to the naked eye are removed are regarded as low-risk patients, and may not be treated with iodine 131 therapy. Iodine 131 treatment is not recommended for low-risk stratified patients, while it is strongly recommended for high-risk patients and considered for intermediate-risk patients. It is recommended that patients consult with their specialists to choose the appropriate treatment plan according to the lesion and systemic conditions, and regular review is needed after treatment.