Diabetic retinopathy(DR), one of the most common diabetes-specific microvascular complications, is classically described by intraretinal microvascular abnormalities and neovascularization. It is the main reason why visual impairment and blindness in people aged 20-65 years worldwide. Glycolysis can provide energy by converting glucose into pyruvate. Endothelial cells mainly utilize glycolysis to produce ATP to maintain the function, including forming tight junctions and barrier functions. Pyruvate kinase(PK)M2(M2 isoform of pyruvate kinase)is a key enzyme of glycolysis and is widely expressed in most tissues. As major cellular components in the retina, endothelial cells and photoreceptor cells play a crucial role in the occurrence and development of DR. Studies have shown that PKM2 takes part in the development of DR by regulating the function of endothelial cells and photoreceptors in metabolic and non-metabolic ways. Therefore, this article overviews the role of PKM2 in DR from the direction of endothelial cells and photoreceptor cells and provides new insight into the diagnosis and treatment of DR.