To describe the crack tip failure zone of polymer bonded explosive (PBX), modeⅠcrack tip failure zone of PBX were studied based on the Mohr-Coulomb, Twin-shear and Drucker-Prager strength criterion. The expressions describing the crack tip failure zone of the tension-compression asymmetry for PBX were obtained. Results show that the Drucker-Prager strength criterion takes into account the factors such as tension-compression strength ratio, average stress and deviatoric stress, the solving crack tip failure zone is the biggest. The tension-compression ratio of the material has a significant effect on the crack tip failure zone, the smaller the tension-compression ratio, the more serious the tension-compression asymmetry of materialis, the greater the crack tip failure zone. The temperature has great influence on the mechanical properties of PBX materials, and the crack tip failure zone at 60 ℃ is significantly larger than that at 20 ℃.