To calculate a physical value regarding rigidity of a tire model in a short time.

A tire simulation method is a simulation method for calculating rigidity of a tire 2 having a tread part 2a by using a computer 1. The simulation method comprises a step S1 for inputting a tire model 21 in which the tire 2 including the tread part 2a is modeled by the finite number of elements Bi having nodal points 28, a step S3 for calculating the shape after inner pressure filling of the tire model 21 on the basis of the predetermined inner pressure condition, a step S5 for constraining as non-displaceable at least a part of the nodal points 28 constituting the tread surface 25 of a tread part 22a, among the nodal points 28 of the elements Ei of the tire model 21 after inner pressure filling, and a physical value calculating step S6 for calculating a physical value regarding rigidity of the tire model 21 by displacing relatively at least a part of non-constrained nodal points 28 to deform the model tire 21 with respect to the constrained nodal points 28.