Coronary CT is a non-invasive, low-risk and rapid screening method that has gradually become an important means of early screening and follow-up of coronary artery disease. It actually scans the coronary arteries by multi-row spiral CT (MDCT for short) to understand the coronary lesions. Starting from the first international 4-row MDCT in 1998, after the development of 8, 16 and 32 rows, the most advanced MDCT in clinical practice has reached 64 rows. The “rows” refers to the number of arrays of CT scanner detectors. Generally, the more rows, the wider the detector width, and the larger the width completed in one scan. Coronary artery is suitable for: ①Patients with atypical chest pain symptoms, and the diagnosis cannot be confirmed by ECG, exercise stress test or auxiliary tests such as nuclear myocardial perfusion. ②The diagnosis of patients with low risk of coronary artery disease. ③Suspected coronary artery disease, but coronary angiography cannot be performed. ④Screening of asymptomatic patients with high-risk coronary artery disease. ⑤Follow-up after known coronary artery disease or interventional and surgical treatment. Coronary CT cannot be fully equated with coronary angiography. While coronary angiography sees the lumen of the vessel, coronary CT sees not only the lumen but also the vessel wall, so coronary CT provides more information and has unique advantages for measuring coronary calcified plaque load, understanding the coronary vessel wall and extra-coronary conditions, and examining congenital coronary artery developmental abnormalities. Coronary CT is one of the means to screen for coronary artery disease. Not all patients to be diagnosed need to do imaging, the correct approach should still come from clinical to clinical, symptoms are a preliminary screening, for example, 20-year-old women basically no coronary heart disease, coronary angiography or even coronary CT is best to be merciful to be exempted. Then, simple ancillary tests, such as clinical symptoms, electrocardiogram and echocardiogram, can be used to detect problems in more than 90% of patients. Coronary CT is feasible for patients who are initially screened as high-risk. Coronary CT is competent for general screening, and coronary angiography is not necessary for those with normal coronary CT. The easiest diagnosis with the application of coronary CT is soft plaque. For small soft plaques clinical treatment is only required with medications, such as aspirin and statins. It is increasingly common to see clinically multiple fibrous soft plaques with stenosis of about 70%, which are clinically asymptomatic. It is not known whether intervention is needed for such patients, but close observation and intensive pharmacological treatment are required. Patients with acute coronary syndromes, especially those with recent sudden onset angina, are the most at risk, most likely to have abrupt changes, and also the easiest to treat, as coronary CT in these patients usually shows high stenosis and large soft plaques in the coronary arteries. These patients have the greatest benefit from intervention to eliminate the plaque before it ruptures and prevent myocardial infarction. Many experts question the health economics of coronary CT. Most people believe that 80-100 ml of contrast is used for coronary CT, and the same dose of contrast is used for coronary angiography, and that intervention is required when lesions are found. However, many people ignore the fact that a significant number of patients do not undergo coronary angiography after the coronary CT diagnosis of normal coronary arteries. Of course, coronary CT also has its shortcomings, although coronary CT is a non-invasive means of examination, but it also requires the use of X-rays for imaging, it is observed that every time a coronary CT test is received, the radiation dose received by the subject is equivalent to the radiation dose of taking 500-700 X-ray chest films, the incidence of tumors due to radiation will increase, therefore, do not just because Coronary CT is non-invasive, so do not repeat the test; of course, if you do need it, do not worry too much, it is dose-related, we will not send patients to do coronary CT every day like we do ECG and echocardiography, once a year coronary CT should not be too much. Secondly, the clarity and accuracy of coronary artery imaging is not as good as coronary angiography, the small branches of coronary arteries cannot be fully displayed, the dynamic observation of coronary blood flow is not as good as coronary angiography, especially the images are not clear when the heart rate is fast, arrhythmia or heart failure, and the assessment of restenosis in coronary stents is limited. In addition, the most important thing is that cardiac CT is only an examination tool, while coronary angiography can be performed simultaneously for interventional treatment of suitable lesions. Therefore, cardiac CT can be chosen for patients who cannot undergo coronary angiography and are not clinically inclined to coronary artery disease but need to rule out coronary artery disease and evaluate the efficacy after intervention or bypass surgery, while coronary angiography should be preferred for patients with high clinical suspicion of coronary artery disease who are likely to need simultaneous intervention.