The head and neck are densely populated with all kinds of important organs. Over the past decades, based on more experience in tumor treatment, head and neck surgery has improved the quality of postoperative survival and reduced surgical complications by reducing classical radical surgery, developing minimally invasive surgery, and functional preservation surgery while ensuring the cure rate. The common complications of thyroid surgery, cervical lymph node dissection, parotid surgery and hypopharyngeal surgery in head and neck surgery are briefly introduced. 1, thyroid surgery complications Thyroidectomy is the main measure to treat thyroid disease. Due to the continuous development of surgical techniques and better understanding of thyroid anatomy and pathology, thyroid surgery is safer and the incidence of postoperative complications is greatly reduced. Thyroid surgery has undergone a major historical change in terms of technique and complication occurrence. In the early 20th century, the major complications of thyroid surgery were bleeding and postoperative infection; by the mid-20th century, with the continued maturation of thyroid surgery techniques and the invention and application of effective antibiotics, thyroid surgery had become the safest and most effective procedure. The main postoperative complications today are mainly damage to the recurrent laryngeal nerve (hoarseness) and hypoparathyroidism (hypocalcemia); postoperative death is very rare. Hoarseness is one of the common complications with an incidence of 0.1%-1.1%, mainly due to injury to the recurrent laryngeal nerve and, to a lesser extent, due to hematoma compression or pulling of scar tissue. In the former case, symptoms appear immediately after waking up from intraoperative or general anesthesia, while in the latter case, symptoms appear only a few days after surgery. The incidence of permanent laryngeal nerve injury after total thyroidectomy is 0.3%-1.7%; the hoarseness caused by contusion, pulling or hematoma compression is mostly temporary and can be gradually recovered in 3-6 months by physical therapy, etc. 2.Surgical complications of cervical lymph node dissection Head and neck cancer is prone to cervical lymph node metastasis, and cervical lymph node dissection is an important measure to treat cervical lymph node metastasis of head and neck cancer. Since the neck is densely populated with blood vessels and nerves, the main surgical complications vary according to the scope of surgical resection. Cervical lymph node dissection is divided into radical cervical dissection, modified cervical dissection, elective cervical dissection and extended cervical dissection according to the scope of surgical dissection. In addition to the removal of adipose tissue and lymph nodes in the neck, radical neck dissection and extended neck dissection also remove more neurovascular muscle tissue such as sternocleidomastoid muscle, internal jugular vein and paraspinal nerve. In contrast, modified neck clearance and elective neck clearance can preserve the sternocleidomastoid muscle, internal jugular vein, paraspinal nerve, or one or two of the above three. Paracervical nerve resection can cause shoulder pain and difficulty in lifting; sternocleidomastoid muscle resection can cause neck depression; internal jugular vein and external jugular vein resection can cause head and face swelling; and cervical plexus nerve resection can cause neck and no sensation in the ear. 3.Complications of parotid surgery The main complications of parotid surgery are facial palsy, salivary fistula, earlobe numbness and gustatory sweating syndrome. Parotid surgery often operates on the surface of the facial nerve. If the trauma is too great or excessive strain is applied, nerve paralysis of all or some branches of the facial nerve can occur, and symptoms such as inability to close the eyes or crooked corners of the mouth can occur. Functional training to promote recovery is also important, such as daily massage of the facial muscles, try their best to raise the eyebrows, frown, open and close the eyes, expand and contract the nostrils and show teeth and other movements. 4.Laryngeal and hypopharyngeal surgery complications Surgery is the main treatment for laryngeal and hypopharyngeal cancer, and pharyngeal fistula is one of the most common surgical complications. After laryngeal and hypopharyngeal surgery, regardless of total or partial resection, pharyngeal fistula may occur, mostly within 2 weeks after surgery. The diagnosis of pharyngeal fistula is established if saliva is seen after opening or if blue color is seen from the neck after taking oral melanoma. After the formation of pharyngeal fistula, the wound needs to be opened to clean the pus, and iodoform gauze can be used to fill in the direction of the fistula to change the medicine, and then pressure bandage, nasal nutrition. After the inflammation is under control, a small fistula will grow in a month or so; a large fistula, if the inflammation is under control, can be repaired.