The incidence of coronary heart disease is increasing year by year,with the mortality rate rank-ing first.Early prevention,diagnosis,and treatment are crucial to reduce the mortality rate.Coronary angiography is the gold standard for diagnosing coronary heart disease and is widely used in clinical practice,but it cannot accu-rately reflect the degree of coronary artery disease.Blood flow reserve fraction(FFR)is currently the reference standard for evaluating coronary artery stenosis function.However,it is an invasive examination that is limited in clinical application due to factors such as complex operation,high cost,multiple side effects related to vasodila-tors,and poor reproducibility.In recent years,non-invasive blood flow reserve scores related to imaging have been increasingly applied in clinical practice.Quantitative flow fraction(QFR)and optical coherence tomography based flow reserve fraction(OCT based optical flow ratio OFR)have become research hotspots.OFR,as a relatively new technology,has received increasing attention.Therefore,this article will describe the basic principles,clinical value,and research progress of the above-mentioned technologies.