1.For atypical chest pain, clinically difficult to confirm the diagnosis, especially those with poor therapeutic effect, as well as middle-aged and elderly patients with enlarged heart, severe arrhythmia, heart failure, abnormal ECG and suspected coronary artery lesion or malformation, but non-invasive examination cannot confirm the diagnosis, coronary angiography can provide a strong diagnostic basis. For asymptomatic but apparently positive exercise test, as well as those resuscitated from primary cardiac arrest, coronary artery and left ventricular angiography should be performed to confirm the diagnosis. 2.For patients with clinically confirmed coronary artery disease, when percutaneous transluminal coronary angioplasty (PTCA), stent implantation or aorta-coronary artery bypass grafting is considered, coronary artery and left ventricular angiography must be performed first to clarify the site and extent of the lesion and the function of the left ventricle, so as to correctly select the indications and formulate the treatment plan. 3, for non-coronary heart disease before surgery: for patients with valve disease aged 45 to 50 years or older, or aortic lesions combined with angina pectoris, certain congenital heart disease or obstructive hypertrophic heart disease, clinical manifestations of cardiac ischemia or chest pain in middle age or older, coronary angiography should be performed before surgery.