The invention discloses a method for calculating contrast 
blood flow reserve fraction based on contrast images. The method comprises the following steps: measuring pressure Pa of a coronary 
artery port of a heart through a 
blood pressure sensor; acquiring two-dimensional 
pipe diameter and length of a 
blood vessel through the contrast images, generating a three-dimensional 
blood vessel grid model through two contrast images with included angles of 30 degrees or more, and acquiring the three-dimensional 
pipe diameter and length of the 
blood vessel; measuring time taken by blood containing contrast agents moving from a starting point to an ending point of a specified blood vessel, and calculating 
blood flow velocity V<1> according to the time and the three-dimensional length of the blood vessel; and taking the 
blood flow velocity V<1> as a coronary 
artery inlet flow velocity to calculate pressure drop 
delta P<1> from a coronary 
artery inlet to a coronary artery 
stenosis distal end, calculating average pressure P<d1> in the coronary artery 
stenosis distal end through a formula of P<d1>=Pa-
delta P<1>, and calculating the contrast blood flow reserve fraction through a formula of cFFR=P<d1> / Pa. Therefore, cFFR and resuming Pd / Pa can be obtained by conventional contrast images without use of vasodilators.