I. Concept: As the name implies, bypass surgery takes the patient’s own blood vessels (internal thoracic artery, saphenous vein of the lower extremity, etc.) and connects the distal end of the narrowed coronary artery to the aorta, allowing blood to bypass the narrowed part and reach the ischemic area, improving the blood supply to the myocardium, thus achieving the goal of relieving angina symptoms, improving heart function, improving the patient’s quality of life and extending life expectancy. This procedure, also known as coronary artery bypass grafting, establishes a smooth path between the aortic root filled with arterial blood and the ischemic myocardium, which is why it is imaginatively referred to as a “bridge” over the heart, commonly referred to as “bypass surgery”. Role: Coronary artery bypass surgery is a surgical procedure performed for patients with coronary atherosclerotic heart disease to re-establish blood flow channels and improve myocardial blood supply in order to eliminate symptoms and prolong life. Coronary heart patients are ineffective by conventional medical treatment before surgery, emotionally unstable and stressed to lead to repeated occurrence of angina pectoris. Third, preoperative precautions: 1, do not strenuous activities. 2, Quit smoking, quit drinking, quit bad habits in diet, closely monitor blood sugar and urine sugar in diabetic patients, and restrict fatty diet. 3.Training of deep breathing and effective coughing action, patients with respiratory tract infection should be treated actively. 4.Twice daily low-flow oxygen inhalation. 5.Perform cardiovascular angiography for puncture of local skin After the procedure, attention should be paid to the puncture site for bleeding and hematoma formation, generally in the puncture local wrist band compression for 12 hours and bed rest for 24 hours. 6.Keep the bowels open.