The vagus nerve belongs to the Ⅹ pair of cerebral nerves and is a mixed nerve, containing four kinds of fibers: 1. Visceral motor fibers: they belong to the parasympathetic nerves. 2. Visceral sensory fibers. The above two types of nerve fibers have basically the same course and distribution. They exit the brain through the lateral sulcus of the lateral extension, exit the cranium through the jugular foramen, descend to the thoracic cavity along the internal jugular vein and the common carotid artery, and then descend to the abdominal cavity along the surface of the esophagus, and send out branches along the way, which are distributed in the thoracic and abdominal cavity organs. In the thoracic cavity, it is mainly distributed to the heart, lungs and esophagus. In the abdominal cavity, it is mainly distributed in organs such as liver, spleen, kidney, stomach and intestines above the left curve of the colon, and manages the visceral movement and visceral sensation of the above organs.3 Somatomotor fibers are mainly distributed in the soft palate and pharyngeal muscles, etc., which are responsible for swallowing and articulation, etc.4 Somatosensory fibers are mainly distributed in the dura mater, auricle, and external auditory canal, and are engaged in somatosensory sensation. The main branches of the vagus nerve include the superior laryngeal nerve, cervical heart branch and the laryngeal nerve.