Introduction Statins are the most commonly used lipid-lowering agents for patients with coronary artery disease, and they significantly reduce the occurrence of major cardiovascular events (MACE). As evidence of the benefits of statins continues to emerge, guidelines have expanded their indications to include primary prevention, and intensive lipid lowering is advocated for secondary prevention. However, some patients cannot fully meet the lipid standard by taking statin alone, so new lipid-lowering drugs, such as ezetimibe and PCSK9 inhibitors, have become good helpers of statin. By controlling blood lipids well, atherosclerosis can be prevented and the occurrence of coronary heart disease can be reduced. However, it is not better to lower blood lipids as low as possible. Cholesterol and triglycerides are known as “bad lipids”, but both have a role in the body. For example, cholesterol is the raw material for the synthesis of vitamin D. Vitamin D regulates the metabolism of calcium and phosphorus in the human body and is an indispensable substance for human growth and development, and is also the raw material for many important hormones in the body, such as adrenocorticotropic hormone, androgen and estrogen. Low blood lipids can also affect the absorption of vitamins A and E, leading to the phenomenon of premature aging. Therefore, the control of blood lipids should be within certain limits, and blood lipids should not be lowered blindly. Because some patients with hyperlipidemia increase the dosage without authorization in order to lower lipid quickly, they have adverse reactions such as liver function damage. Patients with hyperlipidemia should be treated based on the treatment method of diet + exercise.