Cerebral infarction, commonly known as stroke, is a serious threat to human survival and quality of life, and is one of the major causes of death in China. In patients with cerebral infarction, the ratio of ischemic lesions to hemorrhagic lesions is 4:1, and extracranial carotid stenosis is very closely related to cerebral ischemic diseases, especially stroke. 30% of ischemic strokes are caused by extracranial carotid stenosis, and the 2-year stroke rate can be as high as 26% in patients with symptomatic carotid stenosis >70%.