Today, after more than 30 years of development of coronary intervention, there are many emerging techniques to compensate for the limitations of coronary angiography, the most representative of which is intravascular ultrasound (IVUS) technique, which is not only an important reference value for determining the degree of coronary lesion, whether the plaque is stable, the lumen size, and whether intervention is needed, but also for determining whether the stent fits well after intervention, the degree of lesion coverage, and whether there is tearing. It is also the main tool to determine whether the stent is well-fitted after intervention, the degree of lesion coverage, and whether there is tearing. Coronary endovascular angiography is used to evaluate the degree of endovascular coverage of the stent and the presence of thrombus. OCT, known as optical coherence tomography, is a new high-resolution tomographic imaging modality that combines optical technology with an ultra-sensitive detector that uses near-infrared light to probe intravascular structures at the micron level, applying modern computerized image processing with extremely high resolution that is superior to any existing imaging technology.OCT correlates well with histological structures under light and electron microscopy. It is used in some cardiac centers in the United States and Europe to determine the thickness of unstable plaques in coronary arteries, especially the fibrous cap, and lipid nuclei. It is also currently applied to determine thrombotic changes, intimal tears and the degree of stent apposition after stent placement, the coverage of the endothelium of the stent exposed in the vessel lumen and the relationship between the stent wire and the endothelium of the vessel. The study showed that different observers with OCT were consistent for the same lesion in terms of maximum stent diameter, area, stent metal wire and endothelial thickness coverage, indicating that the technique has good reproducibility and accuracy. The degree of stent apposition in the acute phase after stent placement was evaluated by OCT to clarify the mechanism of stent action on the vessel wall, intra-stent thrombosis, and other conditions, and to determine the perioperative vascular damage. Several months to several years after stent placement, OCT was used to evaluate the effect of stent placement in the medium and long term. OCT technology changed the original concept of reendothelialization of blood vessels within the stent to the concept of endothelial tissue coverage of the stent, and the thickness, area, distribution and thrombus formation of the covered tissue could be detected to determine the degree of endothelial tissue coverage within the stent. Compared with intravascular ultrasound, OCT is superior in determining stent-induced tears, endothelial tissue detachment, and poor stent apposition.