Abstract: Disclosed is a roller taper grinding method for a planetary roller screw mechanism. The method includes steps as follows: step 1: determining basic parameters and a bearing capacity of a planetary roller screw mechanism to be machined; step 2: establishing deformation and force balance equations of the planetary roller screw mechanism according to the basic parameters and the bearing capacity of the planetary roller screw mechanism determined in step 1; step 3: iteratively computing an optimal grinding taper angle of roller grinding according to the deformation and force balance equations established in step 2; step 4: determining process parameters of roller grinding; and step 5: grinding a roller taper of the planetary roller screw mechanism by a machine tool according to the process parameters determined in step 4.