Clinically, thyroid surgery can be classified into grade 1-4 according to the surgical classification, among which grade 3 and grade 4 are major surgeries, and all thyroid surgeries belong to grade 3 and 4, so thyroid surgeries are major surgeries. According to the scope of thyroid gland resection, it can be divided into grade 3 surgery and grade 4 surgery. If the thyroid lesion is benign, the lesion can be removed and the normal thyroid gland can be preserved without peripheral lymph node dissection, which is relatively less traumatic and results in faster recovery and fewer complications. If the patient’s thyroid lesion is malignant tumor, it is necessary to perform total thyroid excision and lymph node dissection, which is more traumatic, and postoperative complications such as incision infection, hoarseness, and low calcium convulsions will occur, which is a level 4 surgery, i.e. major surgery.