A method for measuring fractional flow reserve without a vasodilator, comprising the following steps: measuring the pressure P1 at the coronary artery inlet by means of a blood pressure sensor； acquiring the two-dimensional vessel diameter and length of the blood vessel by means of angiography, and generating a three-dimensional blood vessel mesh model to acquire the three-dimensional vessel diameter and length of the blood vessel； measuring the time taken for blood to flow from a start point to an end point of a blood vessel section, and calculating a blood flow velocity V1 on the basis of the time and the three-dimensional length； calculating the aortic pressure P2 in a maximum hyperaemia state； calculating the blood flow velocity V2 in a maximum hyperaemia state； taking the blood flow velocity V2 as the coronary inlet velocity and the aortic pressure P2 as the coronary inlet pressure Pa, calculating the pressure drop ΔP from the coronary inlet to the distal end of the coronary stenosis, the average pressure in the coronary artery at the distal end of the coronary stenosis being Pd＝Pa-ΔP； and, by means of the formula CAFFR = Pd/Pa, calculating the coronary angiography fractional flow reserve score CAFFR. The advantage is that there is no need to use a vasodilator, and fractional flow reserve can be calculated by means of angiography, aortic pressure, and blood flow.L'invention concerne un procédé de mesure de flux de réserve coronaire sans vasodilatateur, comprenant les étapes suivantes : mesurer la pression P1 au niveau de l'entrée d'artère coronaire au moyen d'un capteur de pression sanguine； acquérir le diamètre et la longueur de vaisseau bidimensionnel du vaisseau sanguin au moyen d'une angiographie, et générer un modèle de mailles de vaisseau sanguin tridimensionnel pour acquérir le diamètre et la longueur de vaisseau tridimensionnel du vaisseau sanguin； mesurer le temps nécessaire pour que le sang s'écoule d'un point de départ à un point d'arrivée d'une coup
