Atherosclerosis is a multifaceted disease involving various cell types and complex mechanisms, and it is the main cause of cardiovascular disease. Proprotein convertase subtilisin/kexin type-9 (PCSK9) has been identified as an effective target for treating atherosclerosis; however, most current research focuses on biological drugs. Our work optimized the previously reported autophagosome-tethering compound OY3, and specifically, compound W6 induced PCSK9 degradation with a 5-fold increase in activity and a 6-fold increase in bioavailability. Compared to the currently marketed PCSK9 drug, siRNA, W6 demonstrated comparable antiatherosclerosis effects both in vivo and in vitro. W6 exhibited beneficial effects on hepatocytes, endothelial cells, macrophages, and vascular smooth muscle cells involved in the atherosclerosis process, making it a promising potential antiatherosclerosis drug. This work highlights the feasibility of ATTECs in degrading both intracellular and extracellular proteins, and our novel PCSK9-ATTEC W6 provides a valuable reference for the treatment of atherosclerotic diseases.