In the middle-aged and elderly population, carotid atherosclerosis is the most common type of vascular disease. The formation of atherosclerotic plaques easily leads to stenosis, occlusion, and embolism formation, and it is closely associated with transient ischemic attack (TIA) and ischemic stroke. Carotid ultrasound is a non-invasive examination means, simple, safe, reliable, low cost and easy to repeat, which can detect carotid lesions at an early stage and evaluate the extent of lesions, and can provide not only morphological information of atherosclerotic plaques, but also information of hemodynamic changes caused by plaques, which has an important guiding role in the diagnosis and treatment of patients with carotid artery disease, and is also a good tool for intracarotid intervention or endothelial It is also a good follow-up tool after carotid intervention or endothelial debridement. It is now the preferred means of screening for carotid artery disease. Carotid ultrasound is very necessary for middle-aged and elderly people who have high blood pressure, hypertension, diabetes, history of fainting, frequent dizziness, pain, and early manifestations of stroke (transient eye blackness, numbness of one limb, speech impairment, sudden mouth distortion, etc.).