Functional imaging techniques have been continuously developed based on optical coherence tomography (OCT). OCT angiography (OCTA) technique employs the relative motion of red blood cells and surrounding tissues as the endogenous label for blood flow. By analyzing the dynamic optical scattering characteristics of spatially scattered signals in OCT, the blood flow motion information is extracted. Thus, OCTA enables an in vivo, label-free, and 3D high-resolution blood flow imaging by distinguishing dynamic blood flow areas and surrounding static tissues in three-dimensional space. The optical attenuation coefficient (OAC) algorithm evaluates the degree of tissue damage and accurately reveals tissue activity by analyzing the attenuation characteristics of spatially scattered signals in OCT with depth. OCTA technology and OAC algorithm enable in vivo, label-free, 3D high-resolution, and long-term monitoring of stroke progression in real time, including real-time assessment of ischemia and blood flow reperfusion, and tissue damage and its degree of recovery. A systematic review is made on the development of OCTA technology and OAC algorithm, and the progress of related stroke research is further introduced. The above-mentioned OCT technology has important application value in the field of biomedicine.