Optical coherence tomography (OCT) is the latest intravascular optical scanning tomography technique used in clinical practice. The principle is similar to Intravascular ultrasound (IVUS), which uses an energy beam to scan 360° circumferentially in the lumen of the vessel to obtain a cross-sectional image of the vessel. OCT is also known as optical biopsy because of its high resolution, which is by far the highest resolution intravascular imaging technique with a resolution of about 10µm, 10 times higher than the resolution of intravascular ultrasound imaging and close to the observed tissue level. The evaluation of both immediate and long-term vascular repair after stenting. OCT evaluation of tubular atherosclerotic plaques OCT’s high contrast and high resolution of tissue structures, as well as its ability to penetrate severely calcified tissues, can provide image data at a level close to histological resolution, and can identify morphological changes in the vessel wall and lumen, including intima, lumen size, vulnerable plaque identification, vascular OCT can provide more and finer morphological information than IVUS, improve the level of understanding of plaque characteristics, especially facilitate the identification of vulnerable plaques and guide clinical treatment. 2. Evaluation of OCT in the immediate post-stenting period After stenting, the expansion of the balloon will form extrusion damage to the endothelium of the vessel, which may form a sandwich in the proximal or distal end of the stent, and tissue prolapse in the stent The stent expansion may be compromised by heavily calcified lesions or by poor stent apposition. Immediate postoperative coronary angiography and IVUS are limited by resolution and do not effectively identify these lesions, which may also lay the groundwork for acute or subacute in-stent thrombosis after surgery. OCT, with its high resolution, can accurately evaluate the immediate post-stenting period, detecting interstitial lesions and poor stent apposition that cannot be detected by IVUS and CAG, guiding the intervention process, evaluating the immediate results, ensuring the quality of the procedure, and reducing postoperative complications, especially the occurrence of intra-stent thrombosis. However, there are increasing reports of late thrombosis due to incomplete intimal coverage of the stent surface after placement of drug-eluting stents, sometimes due to excessive inhibition of proliferation. There is also no uniform understanding of how long it takes to take the antiplatelet drug clobigrel. OCT, with its high resolution, can provide accurate information on endothelial coverage after drug-eluting stenting. Although there are no large-scale clinical studies to confirm the application value of OCT in the evaluation of long-term intravascular repair after stent placement, the available information from relevant clinical studies shows that OCT for evaluating the effect of stent treatment and its intimal repair in the era of drug-eluting stents is incomparable to other examination methods. In conclusion, OCT imaging system can clearly show the characteristics of various coronary atherosclerotic plaques, and it is clinically important to evaluate whether the stent support rod is attached to the wall, stent position coverage, tissue tear, tissue prolapse, in-stent restenosis and observation of thrombus after stenting (especially drug-eluting stents). It is expected to be an ideal tool for evaluating unstable plaques and assessing the effectiveness of stent treatment.