Cerebrovascular stenosis is usually categorized as mild, moderate, or severe, and is not judged by the clinician, but by some auxiliary tests, such as carotid ultrasonography, nuclear magnetic resonance of blood vessels, and total cerebral angiography for grading. Severe stenosis is >70% of the internal carotid artery and requires surgical intervention, which consists of two types of interventions, one of which can be minimally invasive stenting of the carotid artery with balloon dilatation, and the other is carotid endarterectomy, which involves cutting out the stenotic portion of the carotid artery. Mild and moderate stenosis are usually caused by atherosclerotic plaques, which are related to heredity, perennial habits and age, and most of all the increase of cholesterol leads to atherosclerotic plaques, so the treatment is also stratified for different grades.