Diabetic macular edema (DME) is caused by diabetes, featured by retinal thickening or hard exudates at macular center within 1D. It is one of the main reasons for decreased vision of diabetic retinopathy(DR). Its pathogenesis is speculated to be the damage of retinal inteernal and external barrier, as well as the role of cytokines. There are many checks that can make the diagnosis of macular edema, including fundus fluorescein angiography(FFA), heidelberg retina tomography (HRT), optical coherence tomography (OCT) and so on. Laser treatment is still the most widely used method of treatment. DEMs more effective treatment methods have always been being clinically explored.Applications such as intravitreal injection of corticosteroid drugs, as well as co-vitrectomy retinal internal limiting membrane peeling surgery and other treatments in combination, have now achieved a good result. Despite that the treatment of DME is in great progress, it apparently still needs more effective treatment measures of less side effects.