“Microvascular decompression” is a surgical method to separate the nerve and blood vessels that are compressing each other. It was first proposed by Professor Jannatta in 1967 and has become the standard treatment for trigeminal neuralgia and facial spasm. Its advantage is to release the local vascular compression and eliminate the symptoms while preserving the normal sensory and motor conduction functions of the trigeminal and facial nerves. Bao Yuanhai, Department of Neurosurgery, Xuanwu Hospital, Capital Medical University Nerves and blood vessels are densely packed in the skull. If the nerves and blood vessels ride on each other, the pulsation of the blood vessels will lead to short circuiting of the nerves, increased excitability of the trigeminal nerve and facial nerve, and trigeminal neuralgia and facial muscle spasm will occur. The blood vessel that compresses the nerve and produces pain is called the “responsible vessel”, and the common responsible vessels are: superior cerebellar artery, anterior inferior cerebellar artery, posterior inferior cerebellar artery, vertebral artery and so on. The responsible vessel can be one or more than one, and it can be either an artery or a vein. Under general anesthesia, a 4-cm longitudinal incision is made behind the affected ear and within the hairline, and a small hole as large as a copper coin is opened in the skull, with a diameter of about 2-3 cm. Once the responsible vessels are isolated, the root cause of the irritation disappears and the hyperexcitability of the trigeminal and facial nerves will then disappear. In the majority of patients, the facial pain or spasm disappears immediately after surgery and normal facial sensation and function are preserved, without affecting the quality of life. The whole procedure takes about two hours. Microvascular decompression is the only method to treat the cause of trigeminal neuralgia and facial spasm and to preserve the anatomical integrity of these nerves. Because of its obvious effect, non-destructive nature, few side injuries, and extremely low recurrence rate, microvascular decompression is currently the safest and most effective method internationally recognized for the treatment of trigeminal neuralgia and facial spasm. Except for patients who cannot tolerate surgery, all other patients with trigeminal neuralgia and facial spasm are suitable for microvascular decompression surgery. The most common surgical complications include hearing loss and facial sensory loss, but with the improvement of microsurgical techniques, such complications are less than 5% in large neurosurgical medical institutions.