A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed here. This method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments with fiber tension are wound layer by layer, and consider the effects of accumulated stress and deformation during filament winding on the bursting strength of composite case. Taking ∅520 mm composite cases as a case study, the filament-winding-process-induced stress and deformation as well as progressive damage behavior are numerically predicted, followed by a comparison with experimental results. The numerical results show that the predicted bursting pressures for composite cases manufactured on the mandrels with and without a flexible component are 14.20 MPa and 21.40 MPa, respectively. These values exhibit slight deviation from the measured pressures of 13.50 MPa and 21.57 MPa. Moreover, the predicted damage locations, situated respectively in the dome and cylinder, agree well with the experimental observation. These observations indicate that use of flexible component reduces the load-bearing capacity of the domes. Furthermore, it validates the reliability and accuracy of the proposed numerical method in predicting the bursting strength of composite cases.