Optical coherence tomography(OCT)is one of the fastest growing techniques in ophthalmic imaging field. With the gradual improvement and update of OCT technology, optical coherence tomography angiography(OCTA)has emerged. It serves as a valuable diagnostic tool for retinal and choroidal neovascularization-related disease. This article reviews the principles of OCTA, OCTA imaging of microaneurysms(MAs), retinal ischemia, retinal neovascularization(RNV)in patient with different stages of diabetic retinopathy, and the limitations and future prospects of OCTA.