For heart bypass patients, surgery is only the first step of treatment, and reasonable drug treatment after surgery is crucial. First, antiplatelet drugs for patients with coronary artery disease have high blood viscosity, which slows down the coronary circulation and makes them prone to platelet aggregation and thrombosis. Anti-platelet therapy is essential to maintain and improve the long-term patency of the grafted vascular bridge. Second, β-blockers β-blockers can prevent exercise or emotion-induced angina pectoris and reduce mortality and sudden death after acute infarction by slowing down heart rate, inhibiting myocardial contractility and reducing myocardial oxygen consumption, which can greatly help to improve the long-term survival rate of patients. Angiotensin-converting enzyme inhibitors (ACEI) Because ACEI preparations not only have antihypertensive effects, but also help ventricular remodeling, it is recommended that postoperative patients should take them as prescribed by their doctors, especially for patients with left ventricular EF less than 40%, or with hypertension, diabetes mellitus, and chronic renal insufficiency. Fourth, nitrate preparations nitrate drugs are a class of drugs commonly used in patients with coronary artery disease, its basic effect is to directly relax vascular smooth muscle, reduce the anterior and posterior myocardial load, reduce myocardial oxygen consumption, so as to improve the oxygen supply to the ischemic myocardium. Fifth, other drugs such as antihypertensive drugs, lipid-lowering drugs and blood sugar-lowering drugs, etc., the doctor will choose according to the specific circumstances of the patient.