The diagnostic criteria of coronary artery disease are as follows: 1. Typical clinical symptoms: exertional angina manifests itself more often after exertion, lasts 3-5 minutes, is suffocating in the anterior region of the upper middle sternum, sometimes there can also be symptoms of back pain, and in severe cases it can also occur at rest, and is accompanied by symptoms of heavy sweating and shortness of breath; 2. Examination: ischemic changes in the ST-T segment are mostly present in the electromyogram during the attack of coronary artery disease, coronary artery Coronary angiography is the gold standard for diagnosis, and coronary CTA can also be used for preliminary screening of coronary heart disease. If ischemic changes are found in the ECG on physical examination, further ambulatory ECG can be performed to assess the presence of severe ischemia. Coronary angiography allows direct visualization of the patient’s coronary vessels, allowing visual determination of the degree of stenosis and the presence or absence of occlusion. For coronary angiography, a stenosis of 50% or more can be clearly identified as coronary artery disease, and a diagnosis of coronary artery disease can be made.