Abstract: Taking the last-stage blades in the expander of compressed air energy storage（CAES） system as research object, based on centrifugal force conditions, an efficient equivalent crown constraint model was proposed and the simulation results of the cyclic symmetry constraint model and the multi-blade model were compared. Simultaneously, a constitutive program capable of simulating elastoplasticity and failure behavior was developed. Results show that compared with other models, the simulation results of the equivalent crown constraint model are close to the full-size model results, showing both precision and efficiency advantages. The written constitutive subroutine can effectively simulate the deformation-load response curve of 17-4ph steel. Specifically, when failure begins to occur at about 1/4 of the radial position of the blade, the failure area grows rapidly.