Diabetic macrovascular disease is a complication of diabetes,with the highest incidence,the most harmful and the highest death rate. Subclinical hypothyroidism (SCH) is defined as a plasma thyroid-stimulating hormone (TSH) level above the institutional reference range combined with a plasma free thyroxine (FT4) or free triiodothyronine (FT3) level. In recent years, domestic studies have shown that elevated TSH can be used as an independent risk factor for atherosclerosis (As) through a variety of ways to promote the development of As, and thus participate in the progress of diabetic macroangiopathy. This article reviews the association between SCH and atherosclerosis in diabetic patients by summarizing the relevant literature.