The most commonly used 2nd generation stent is the drug-coated stent, which has a lower incidence of restenosis and is suitable for most patients. Generation 2 stents are mainly given coated stents, including bio-coated stents and drug-coated stents. Bio-coated stents may still irritate local vascular tissues, leading to the development of inflammatory and immune reactions, while drug-coated stents can effectively avoid the above situations, so they are more widely used. The metals chosen for drug-coated stents are mainly nickel-titanium alloy or cobalt-chromium alloy, and the drugs coated on their surfaces are heparin, hirudin, rapamycin, paclitaxel, and so on. In recent years, the use of drug-coated stents has been gradually popularized, and they are suitable for most of the population, but they may not be the best choice for patients who are not suitable for long-term use of drugs because they still need to apply anti-platelet aggregation drugs for a long period of time after the operation. In recent years, the 3rd generation of biodegradable stents has been applied in the clinic, and whether it can become the mainstream stent in the future still needs long-term clinical practice to be verified.