Moyamoya disease (MMD) is a group of occlusive diseases characterized by progressive stenosis or occlusion of the terminal internal carotid arteries and their large branch vessels bilaterally, and the formation of an abnormal neovascular network at the base of the skull. The name “smog” comes from the fact that the cerebral angiogram shows a fuzzy mesh-like shadow at the base of the brain due to abnormal capillary growth, which resembles a puff of smoke from a cigarette, hence the name. Moyamoya is the Japanese pronunciation of “smoke”. Other names for this disease include: smog syndrome, smog-like syndrome, pediatric WiIIis’ ring occlusion, and pediatric idiopathic progressive Willis’ ring occlusion. The clinical manifestations are mainly divided into two categories: hemorrhage and ischemia, with a bimodal distribution of the age of onset between 5 and 40 years old. The essence of the disease is occlusion of the arterial trunk at the base of the brain with compensatory vascular proliferation. Non-surgical treatment 1.Ischemic patients use vasodilators; for hemorrhage patients, lowering cranial pressure and hemostasis are the main focus. If the cause is clear, the cause should be treated actively. 2.Surgical treatment: If intracranial hematoma is formed, it should be removed in time. Ischemic patients can be considered for revascularization surgery: including direct revascularization surgery, indirect revascularization surgery and combined revascularization surgery. (1) Direct revascularization surgery (direct vascular bypass surgery)— Directly connect the blood vessels on the scalp (such as superficial temporal artery and occipital artery) to the branches of intracerebral arteries (such as anterior and middle cerebral arteries, or posterior cerebral artery and posterior inferior cerebellar artery), among which superficial temporal artery-middle cerebral artery (STA-MCA) is the most common. (2) Indirect vascular bypass surgery (indirect vascular bypass surgery) — Applying extracranial blood-rich tissue to the brain, commonly used include brain-dural-artery applanation (EDAS), brain-dural-artery-muscle applanation (EDAMS), banded EDAMS, brain-muscle applanation (EMS), and brain-muscle-artery applanation (EMAS). (3) Combined revascularization procedures: such as combining STA-MCA reconstruction with EDAS, etc.