Coronary heart disease, known as coronary atherosclerotic heart disease. As the name implies, it is the hardening and narrowing of the coronary arteries in the heart, resulting in insufficient blood supply to the heart muscle and producing symptoms such as chest tightness and chest pain or even myocardial infarction. When the lesion is so severe that it cannot be treated with oral medication or cardiovascular stents, coronary artery bypass surgery, or bypass surgery in short, is required. The difference is that the water pipe does not move, while the blood vessels in the heart are constantly beating with the heart, which makes it extremely difficult to connect the “water pipe”. So, the physicians came up with two methods: 1. using the artificial heart-lung machine with extracorporeal circulation to simulate the heart-lung work, while the patient’s own heart stops beating, and the physician performs surgery on the stopped heart, which is coronary artery bypass surgery under extracorporeal stoppage (CABG); 2. the physician uses the fixator to make the local myocardial contraction weaken, so that the surgery can be performed on the relatively stable heart surface, which is non-external nonstop inferior coronary artery bypass surgery (OPCAB). The advantages of CABG are that the operation is stable, smooth and less technically demanding, but the disadvantage is that the operation requires extracorporeal circulation and the operation is not in the normal physiological state. The disadvantage of OPCAB is that it requires high requirements for physicians and requires experienced physicians to ensure the quality of surgery. From the long-term follow-up, the results of these two surgical procedures are basically similar, and more results need to wait for larger samples and longer studies. Therefore, the current choice of surgical approach is determined by the experience, surgical skills and surgical habits of the surgeon team.