1.Electrocardiogram is an easy, simple, inexpensive and reliable test. It is the most commonly used and simplest test to diagnose coronary heart disease. 2.Electrocardiogram exercise test is used to induce myocardial ischemia with bicycle exercise test and active plate exercise test in order to confirm the existence of angina pectoris and to record the occurrence of arrhythmia and abnormal changes of ECG during angina pectoris attack. This is a simple, practical and reliable method to diagnose coronary heart disease. 3.An ambulatory electrocardiogram is a kind of ambulatory electrocardiogram that the examiner can carry with him/her to record continuously for 24 to 72 hours. The main purpose is to record abnormal ECG changes during angina attack and to detect asymptomatic myocardial ischemia, which has a high diagnostic value for coronary heart disease with an accuracy rate of 50% to 60%. This dynamic and prolonged continuous monitoring recording provides a valuable diagnosis of one-time angina pectoris, arrhythmia and unexplained syncope and palpitations. 4.Echocardiography The test is painless and non-invasive. It can observe the size of heart chambers, wall thickness, ventricular wall activity and left ventricular function, which is meaningful for the diagnosis of coronary heart disease and is one of the most commonly used examination methods at present. 5.Radionuclide mainly includes radionuclide cardiac blood pool imaging and radionuclide myocardial imaging (ECT). It can measure the site and extent of myocardial necrosis or ischemia, as well as the degree of coronary artery obstruction, and also observe the changes of cardiac function of the subject, so as to make a diagnosis of coronary heart disease. 6.Heart CT Coronary artery calcification is a sign of coronary artery atherosclerosis. Ultra-high speed CT can not only show coronary artery calcification and its degree more clearly, but also evaluate the exercise function of the heart and the blood perfusion of the myocardium and coronary arteries, which is more significant for the diagnosis of coronary heart disease. In addition, spiral CT of the heart can also detect coronary artery sclerosis, which is also helpful for the diagnosis of coronary heart disease. 7.Left heart function measurement The left ventricular function is measured by simultaneous recording of ECG, phonocardiogram, carotid pulsation and apical beatogram through multi-conductance physiology instrument, which has certain significance for the diagnosis of coronary heart disease. 8.Coronary angiography This test is an invasive test that can clearly diagnose the site of stenotic lesions in each major branch of the coronary arteries and estimate their extent, and is the gold standard for the diagnosis of coronary artery disease. 9, cardiac magnetic resonance imaging CMR) is a multi-functional, highly accurate and reproducible imaging technique that can be used to assess left and right ventricular volumes, overall function, local ventricular wall motion, myocardial thickness, myocardial weight and heart valves, and is particularly suitable for detecting congenital defects, masses and tumors, valves and pericardial lesions. Warm tip: ECG is the earliest and most commonly used diagnostic method in the diagnosis of coronary artery disease. ECG examination equipment is simple, convenient and easily accessible. Whether it is angina pectoris or myocardial infarction, all have their typical ECG changes, especially for the diagnosis of arrhythmia is more clinically valuable. However, one ECG alone cannot make a complete evaluation of heart function, and ECG examination is not a very sensitive method for the diagnosis of coronary heart disease, but must be combined with medical history, symptoms and other examination methods to make a comprehensive and integrated judgment.