Diabetic macular edema (DME) is the main cause of visual impairment in diabetic retinopathy patients. It mainly includes focal DME and diffuse DME, while DME of clinical significance needs timely intervention treatment. Optical coherence tomography is currently recognized as the most sensitive method to accurately diagnose DME. Currently, the common treatments of DME include intravitreal injection of anti-vascular endothelial growth factor (VEGF) or glucocorticoid and laser photocoagulation. Among them, anti-VEGF injection is becoming the first-line therapeutic, and corresponding individual treatment or combined treatment strategy should be selected according to the characteristics of DME and the specific conditions of patients. During the diagnosis and treatment of DME, attention should be paid to the systemic treatment of diabetes and the effect of diabetes-related neuroretinopathy on the therapeutic effect of DME. With the appearance of heterogeneity in the efficacy of anti-VEGF drugs, it remains to be further studied how to choose alternative therapeutics and when to replace them.