The trigeminal nerve is the thickest of the twelve pairs of cranial nerves, and its sensory branch is mainly responsible for the sensation of the face and teeth, divided into three branches: 1) Branch I for frontal sensation; 2) Branch II for zygomatic-cheek, nasal and upper dental sensation; 3) Branch III for mandibular and lower dental sensation. If the trigeminal nerve becomes diseased, the corresponding sensory area will produce pain, which is often electric shock, cutting or burning-like, paroxysmal or continuous, and the pain can last for 24 hours in the late stage. This is the common trigeminal neuralgia. Among them, the II and III branches are the most common, manifesting as cheek, jaw and tooth pain, while the I branch is less common in single attacks; unilateral attacks are common, while bilateral attacks are rare. Patients often have their teeth extracted because of facial and tooth pain, but the pain is not reduced after extraction. Patients may have pain induced by contact with a point on the face (the so-called trigger point). Patients with severe pain cannot comb their hair, wash their face, brush their teeth, eat, or even speak, which seriously affects their daily life. The common causes of trigeminal neuralgia are: 1. intracranial infection: including arachnoiditis, viral infection, etc.; 2. tumor compression or stimulation near the trigeminal nerve: the most common one is cholesteatoma; 3. trigeminal vascular or microvascular compression. Among the above causes, the most common is trigeminal nerve microvascular compression, which accounts for 80%-90% of the causes of trigeminal nerve pain. The trigeminal nerve is surrounded by numerous microvascular branches (including arteries and veins), which can not only compress the trigeminal nerve, but also other cranial nerves and cause corresponding symptoms: compression of the facial nerve can cause facial muscle spasm (often manifested as paroxysmal facial twitching); compression of the auditory nerve can cause postural vertigo and tinnitus; compression of the linguopharyngeal nerve can cause pain in the posterior part of the tongue and pharynx. Compression of the medulla oblongata by some tiny vessels can also cause malignant, refractory hypertension. Trigeminal neuralgia treatment: The treatment of trigeminal neuralgia are: 1, drug treatment: the most effective drug is carbamazepine (Deloitte), short-term effective, but with the increase in the course of the disease and the amount taken also increased significantly, the toxic side effects of the drug also increased significantly, most patients have to stop using. Some allergic patients can cause severe exfoliative dermatitis; 2, trigeminal nerve local closure, sensory root cut, radiofrequency destruction, etc., because of the high recurrence rate is now less used; 3, microvascular decompression: this is currently the most effective method of treating cranial nerve microvascular compression. Microvascular decompression can not only treat trigeminal neuralgia, but also facial muscle spasm, postural vertigo and tinnitus. Patients often have immediate postoperative pain disappearance and low recurrence rate, which is the most used treatment method in the world. According to the statistics of our surgical group in recent years, the pain disappearance rate after using subclavian trigeminal nerve microvascular decompression is over 90%, and the pain recurrence rate is within 5%.