Statins are comprehensive lipid-lowering agents, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. As an effective cholesterol-lowering drug, statins inhibit a key step in the cholesterol biosynthesis pathway and have made outstanding contributions to the prevention and treatment of atherosclerotic cardiovascular disease (ASCVD). The mechanism is to competitively inhibit the endogenous cholesterol synthesis rate-limiting enzyme HMG-CoA reductase, block the intracellular hydroxy valerate metabolic pathway, and reduce intracellular cholesterol synthesis. Additionally, these actions also increase the number and activity of low-density lipoprotein (LDL) receptors on the cell membrane surface and promote plasma cholesterol clearance. Therefore, statins can reduce total cholesterol and LDL levels and reduce triglycerides (TG) to a certain extent and increase high-density lipoprotein (HDL). In addition to lipid regulation, statins may also treat ASCVD by improving endothelial function, Inhibiting inflammation, and stabilizing atherosclerotic plaque. This review summarizes the fundamental roles of statins in ASCVD.