To study the failure and damage behavior of opening mode crack in 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)-based polymer bonded explosive(PBX) under quasi-static loading, a semi-circular bending (SCB) specimen with pre-fabricated crack was designed. The initiation and propagation behavior of cracks in the experiments were studied by digital image correlation method and high speed photography technology of 90000 fps， respectively. Results show that the brittle fracture of sample occurs along the pre-fabricated crack direction, and the strain analysis shows that there is a significant tensile strain concentration region. On the crack propagation path, only the strain evolution of crack tip region has a significant time effect, and the evolution process has a significant inflection point at loading of about 0.85 p_max. The strain concentration effect at the crack tip begins to appear and expand rapidly after the inflection point. There is a significant plastic delaying phenomenon during the crack propagation process. The analyses of strain distribution and evolution characteristics at the crack tip indicate that plastic deformation of TATB-based PBX takes place locally at the crack tip, and the plastic deformation has an obvious influence on the initiation and propagation behavior of the crack.