Heart bypass surgery is the creation of a channel between the proximal and distal ends of a narrowed coronary artery, allowing blood to bypass the narrowed area and reach the distal end, just as a bridge allows a highway to pass unobstructed across a mountain gorge or river. However, the material used is not steel and concrete, but its own saphenous vein, internal mammary artery, right gastroretinal artery, radial artery, and inferior abdominal wall artery. 1.Stenosis greater than 50% of the left main or left main-like lesion. 2.Coronary artery lesion with three branches and stenosis greater than 75%. 3.Coronary artery lesions combined with impaired left ventricular function, which can improve symptoms and cardiac function through myocardial blood flow reconstruction. 4.Complications of myocardial infarction such as ventricular wall tumor, ventricular septal perforation, mitral regurgitation, etc. requiring simultaneous surgical correction. 5.Patients with restenosis or complications after interventional treatment. For patients with unstable angina pectoris, CABG has positive significance in relieving anginal symptoms and improving long-term survival rate. For patients who still have episodic angina after acute myocardial infarction, there are clear indications for CABG surgery because the mortality rate of conventional medical drug therapy for one year is as high as 17% to 50% when considering reischemia in the area of myocardial infarction or ischemia in other sites. There is no final conclusion whether CABG treatment is better than conservative treatment in cases with mild or asymptomatic clinical symptoms, and conservative treatment tends to be preferred in asymptomatic single-branch and double-branch lesions, especially those without combined anterior descending branch lesions. In asymptomatic single-branch and two-branch lesions, especially those without a combined anterior descending lesion, conservative treatment is preferred. If the left ventricular function is normal, many internists as well as patients tend to prefer conservative treatment, although surgeons still advocate surgery.