Diabetic retinopathy(DR)represents the primary cause of blindness among the global working-age population, and the disruption of the blood-retinal barrier is a crucial factor. Research in recent years has elucidated that DR transcends the scope of a mere microvascular disorder into a complex interplay of retinal glial cells and neurodegeneration microvascular pathology. Neuronal damage may precede vascular endothelial changes in the retinal neurovascular unit(RNVU)in the early stage of DR, and glial cell activation further exacerbates vascular barrier dysfunction. Retinal microglia are immune cells that reside in the retina and are involved in chronic inflammatory responses induced by long-term exposure to high glucose levels. Microglia secrete various inflammatory factors in response to high glucose levels, which can lead to the destruction of the blood-retinal barrier structure, increased neuronal apoptosis, and altered gliosis of Muller cells, thus affecting the retina's homeostatic balance. The RNVU has received increasing attention in recent years as a unitary structural study, and the mechanism of microglia in the RNVU and the progress of the study are reviewed.