Moyamoya disease (MMD) is a group of occlusive diseases characterized by progressive stenosis or occlusion of the end of the internal carotid arteries and their large branches bilaterally, and the formation of an abnormal neovascular network at the base of the skull. The name “smoke” comes from the fact that the cerebral angiogram shows a blurred reticular shadow at the base of the brain due to the abnormal proliferation of capillaries, like a puff of smoke from a cigarette, hence the name. 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, and ischemia as the main clinical manifestation in children, while ischemia and hemorrhage are basically the same in adult patients. The essence of the disease is occlusion of the arterial trunk at the base of the brain with compensatory vascular proliferation. Surgical treatment with revascularization is effective.