Thyroid cancer is a common malignant tumor with a high incidence. Lymph node dissection is usually required after total thyroid excision, first of all, lymph node dissection in the central region should be done, as long as the thyroid cancer is conventional. There is also a lymph node dissection in the lateral neck, which usually refers to areas II, III, IV and V. Preoperative ultrasound or CT is needed to evaluate whether there is lymph node metastasis in the lateral cervical area, and if there is lymph node metastasis in the corresponding area, lateral cervical lymph node dissection is needed.