The complement system is a protein response system with a precise regulatory mechanism, which has the functions of mediating inflammation, regulating immune response, dissolving cells and clearing immune complexes. Diabetic retinopathy (DR) is a common and severe ocular complication of diabetes and one of the most common irreversible blinding eye diseases in ophthalmology. The pathogenesis of DR is complex, including hypoxia, oxidative stress, inflammation and abnormal polyol metabolism pathway. In recent years, there has been increasing evidence that DR is closely related to the activation of the complement system. Multiple complement proteins play important roles in key processes such as inflammation regulation and angiogenesis, thereby affecting the pathological process of DR. Therefore, studying the role of complement system and related regulatory proteins in DR Will provide important reference and new ideas for prevention and treatment of DR. This review aims to elucidate the association between multiple complement proteins and the development of DR, as well as the clinical research progress of the targeted complement drugs.