Due to the complexity of motor pattern of mixed-fragments warhead field, it was difficult to get power field related characteristics. We used the ANSYS / LS-DYNA to establish a mixed-fragments warhead power field model, and screened speed, scattering angles and other information with post-processing software LSPREPOST. A computer program was coded to calculate the vulnerability of a particular model of aircraft, taking into account four kinds of damage, such as overpressure, penetration, ignition and detonation, as well as four kinds of warhead. Finally, in condition of the same size of warhead, the double-layer-mixed-fragments warhead obtained the highest kill probability, which provids a theoretical support for the missile warhead design.