Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors regulate lipid metabolism by inhibiting the degradation of low-density lipoprotein receptors on the surface of hepatocytes. Multiple clinical studies have demonstrated that the use of PCSK9 inhibitors as monotherapy or in combination with statins can significantly reduce levels of low-density lipoprotein cholesterol. This article reviews the significant clinical research and progress in the application of PCSK9 inhibitors and briefly summarizes their safety, efficacy and clinical applications.