Coronary artery stenosis is a reduction in the lumen area of coronary arteries caused mostly by coronary artery atherosclerosis. Coronary arteries supply oxygen, fatty acids, glucose and other nutrients needed by the heart’s cardiomyocytes to work normally, so when the coronary artery lumen is narrowed, there can be ischemia and hypoxia of the cardiomyocytes, producing angina symptoms such as chest pain and tightness, and even leading to myocardial infarction and sudden cardiac death in severe cases. If the degree of coronary artery stenosis is greater than 50%, coronary artery disease, also known as coronary atherosclerotic heart disease, can be clinically diagnosed. Age, hypertension, diabetes, hyperlipidemia, smoking, obesity, inactivity and family history are clear risk factors for the development of coronary artery disease. When coronary artery stenosis is between 50% and 75%, coronary blood flow is not yet significantly affected at this time, and we believe that cardiomyocytes can still work compensatively, and patients can receive antiplatelet and lipid regulation to stabilize plaque, while lowering blood pressure, lowering sugar and other risk factor control methods to delay control the progression of coronary heart disease. When the coronary artery stenosis is greater than 75%, the coronary blood flow is significantly restricted and most patients will also have varying degrees of decreased activity endurance and angina symptoms, so coronary artery revascularization should be actively selected. The main methods of revascularization include percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). Specifically, interventional treatment for stenosis includes both traditional drug stents and today’s drug balloons, and for particularly hard stenotic lesions, rotary grinding; bypass treatment includes both traditional open-heart and small-incision treatment, and intervention and surgery can also be performed simultaneously, which we call hybrid surgery. It should be noted that even if coronary blood flow is restored by means of revascularization, lifestyle interventions, i.e., low salt and low fat diet, smoking and alcohol cessation, reasonable exercise, and control of risk factors for cardiovascular disease such as hypertension, hyperlipidemia, and diabetes, are also the cornerstones of treatment. With the progress of coronary interventional techniques, we found that some patients with coronary artery stenosis of more than 75% can be treated medically if there is no significant ischemia (exercise stress test) or no significant reduction in intravascular pressure measurement at both ends of the stenosis, and at this time we need to use special examination methods, such as myocardial nuclear, coronary flow reserve test (FFR), etc. The severity of the stenosis should be fully evaluated after coronary artery stenosis, and the current gold standard for evaluation is coronary angiography. Depending on the degree of stenosis, primary/secondary preventive treatment for coronary artery disease should be performed under the advice and guidance of a physician.