Abstract: Atherosclerotic cardiovascular disease (ASCVD) is one of the most common cardiovascular diseases in the clinic. Its pathogenesis is mainly related to atherosclerosis. Therefore, lowering cholesterol and low-density lipoprotein and delaying the progression of atherosclerosis are basical for the prevention and treatment of ASCVD. Statins are the first choice for clinical treatment. But long-term clinical practice found that some ASCVD patients have unsatisfactory lipid-lowering effects, or cannot tolerate the maximum dose of statins, so it is necessary to seek other treatment methods to prevent cardiovascular diseases. In recent years, it has been proved that PCSK9 inhibitor has a good hypolipidemic effect, especially on low-density lipoprotein. The clinical phase Ⅱ and phase Ⅲ trials have confirmed its good safety and tolerance. This article reviews the relationship between PCSK9 gene and cardiovascular disease, the basic research and clinical application of PCSK9 inhibitors, and the adverse reactions of PCSK9.