Blood flow is the vital indicator to measure the body′s physiological functions and pathological condition. Blood flow testing requires an effective, live, unmarked, capillary level three-dimensional blood flow perfusion weighted imaging approach. Optical coherence tomography angiography (OCTA) technique uses the relative motion of red blood cells and the surrounding tissue as an endogenous marker of blood flow to replace conventional exogenous fluorescent markers. The spatial scattering signal acquisition capability of the optical low-coherence and the motion recognition capabilities of the dynamic optical scattering technology are comprehensively utilized to identify dynamic blood flow area in three-dimensional space, exclude the static surrounding tissue, achieve a living, unmarked, three-dimensional optical blood flow angiography, and obtain capillary blood flow perfusion morphology structure and physiological function information of the capillary level rapidly. This paper systematically reviews the mass sample OCTA technique that primarily includes the motion contrast mechanism of unmarked blood flow angiography, a detection method for high-sensitive tiny blood flow motion, an effective strategy for parallel acquisition of independent mass samples, and the application research of this technique on cortex blood flow imaging.