Optical coherence tomography angiography (OCTA) is a new noninvasive imaging method, which does not require dye injection and can thus be repeatedly used. It can present the fundus vascular network system including capillaries with high resolution and sensitivity. Its axial resolution up to micron level enables us to locate the primary location of lesions in the retina and choroid. OCTA can provide the same or even better vascular observation effect as the current gold standards. Therefore it has been developed rapidly, and its commercial products and applications in clinical practice have appeared. In order to help the relevant personnel quickly understand this technology, this paper introduces its principle and methods, applications in ophthalmology, current situations of products and clinical applications, existing shortcomings and prospects.