Thyroid surgery belongs to several levels of surgery, depending on the specific nature of the thyroid lesions, the surgical classification also varies. First, if the thyroid cyst or thyroid nodule, adenoma surgical treatment, intraoperative resection of the lesion, rapid frozen section examination suggests that the thyroid lesion is benign lesions, then there is no need to carry out a peripheral lymph node clearance, and only carry out the thyroid lesion can be resected. At this time, the thyroid surgery is a tertiary surgery. Second, if the rapid frozen section of thyroid surgery suggests malignant tumor of thyroid, it is often necessary to carry out the central group and cervical group of lymph node clearance, laryngeal reentry nerve exploration, the operation is more traumatic, more difficult and relatively complex, and this time, the operation belongs to the fourth level of surgery.