Hemifacial spasm (HFS), also known as facial muscle twitching, refers to the facial nerve innervated hemifacial muscle episodes of recurrent involuntary twitching, or even spasms or tonic seizures; the onset of the disease begins with the orbicularis oculi muscle and gradually extends downward to the orbicularis oris muscle and facial expression muscle. It can be aggravated by fatigue and tension, especially when speaking and smiling, and with the prolongation of the disease, some cases can have different degrees of facial paralysis. Facial muscle spasm progresses slowly after the onset, and usually does not remit automatically. Treatment includes: 1. Medication: commonly used drugs include methylcobalamin capsules, carbamazepine, thiopride hydrochloride, clonidine, haloperidol, benzhexol, etc. Some patients will have certain effect at the beginning of the disease, but with the prolongation of the disease, the efficacy will gradually diminish, or because they can not tolerate the side effects of drugs and stop. 2.Botulinum toxin treatment: Botulinum toxin is injected into the upper and lower eyelids to reduce the degree of spasm. The effect is obvious in the short term after Botulinum toxin injection, and most patients relapse after one to several months. 3.Surgical treatment: microvascular decompression of the facial nerve root via the posterior cranial fossa is effective, not easy to recur, rarely causes facial sensory disorders, and with the development of the surgical microscope, the chance of complications is very low, and is accepted by more and more patients. The core principle of this type of surgery is that the blood vessel loops compressing the facial nerve root are separated under the microscope, and then a special Teflon spacer is inserted to isolate the blood vessel from the nerve, which completely removes the compression of the blood vessel on the facial nerve and relieves the patient’s pain. Indications for microvascular decompression surgery for facial muscle spasm: 1. primary facial muscle spasm, onset for more than six months, ineffective by medical treatment or continues to worsen, affecting normal life and interaction, patient has the requirement for surgery. 2. no history of facial nerve injury. 3. exclude more serious systemic diseases such as more serious liver, kidney and cardiovascular diseases, able to tolerate this surgery. 4. exclude bleeding diseases and bleeding factors. The presence of hemorrhagic diseases and bleeding factors should be excluded.