Abstract: Dyslipidemia is one of the common metabolic disorders in type 2 diabetes mellitus, often coexisting with insulin resistance and central obesity to form metabolic syndrome, significantly increasing the risk of macrovascular and microvascular complications in diabetic patients. Non-high-density lipoprotein cholesterol (non-HDL-C) refers to the sum of cholesterol contained in other lipoproteins except high-density lipoprotein cholesterol (HDL-C). In recent years, the importance of non-HDL-C in the management of diabetic complications has garnered increasing attention, and it has been established as a major lipid-lowering target along with low-density lipoprotein cholesterol (LDL-C) in the latest expert consensus on lipid management for Chinese diabetic patients. Clinical studies have demonstrated that non-HDL-C is closely associated with residual cardiovascular risk and recurrent stroke risk in diabetic patients, as well as carotid plaque vulnerability and the development of peripheral arterial disease. Additionally, non-HDL-C is also closely related to diabetic nephropathy and retinopathy in type 2 diabetes mellitus, and achieving long-term control of non-HDL-C levels can reduce the risk of chronic kidney disease. This article summarized the relationship between non-HDL-C and complications of type 2 diabetes mellitus and elucidated its significance as a future clinical therapeutic target.