By using split Hopkinson pressure bar (SHPB) device, the dynamic compression experiments of polymer bonded explosive (PBX) simulants were performed under high strain rates (1763~2650 s^-1) loading. Sine pulse of the incident bar was obtained with a lead pulse shaper. The stress states on both ends of the specimen were monitored by polyvinylidene fluoride(PVDF) pressure sensor, respectively. The deformation and failure process of the specimen were shot by high speed camera, and the axial strain of the specimens was monitored by the laser displacement meter. Mesoscopic structure morphology and damage model of the specimen were observed by electron microscope. Results show that the PBX simulant is sensitivity to strain rates. Combining with interface debonding and crystal fracture theory, the grain fracture and the separation between grain and binder are mainly mesoscopic damage model for the PBX simulant.