The vast majority of 90% stenosis in the middle part of the circumflex branch requires percutaneous intracoronary intervention to open the stenotic vessel, while some are too diffuse to be implanted and require coronary artery bypass grafting surgery. The circumflex branch is one of the most important blood vessels supplying blood to the heart. If stenosis occurs, it can cause myocardial ischemia or even myocardial infarction. 90% of the stenosis is in the severe stage, which needs to be opened surgically or change the blood transport pathway. 1. If the stenosis is limited, percutaneous intracoronary intervention is preferred, which can be performed with a medicated balloon to dilate the blood vessel or with an intracoronary stent implantation. 2. If the lesion is diffuse and the effect of stent implantation is poor, coronary artery bypass grafting can be performed by selecting venous vessels of the lower limbs to be implanted at both ends of the lesion, so that the blood flow avoids the stenotic vessels and runs through the implanted vessels. 3. After the success of the above treatments, patients need to take long-term medication to consolidate the effect and prevent the progression of the disease. Such as anti-platelet aggregation drugs, such as aspirin enteric-coated tablets, clopidogrel, tegretol, early often two combined. Lipid-lowering plaque stabilizing drugs, such as atorvastatin calcium, resuvastatin, etc.; expansion of coronary vascular drugs, such as isosorbide nitrate tablets, isosorbide mononitrate; control the heart rate, reduce myocardial oxygen consumption of drugs, such as metoprolol, bisoprolol and so on. 4. Normally, we should also pay attention to light diet, weight control, appropriate exercise, quit smoking and drinking, sleep on time, and maintain a good mood. The above drugs should be taken under the guidance of a doctor.