This research focuses on the engineering characterization of plasticized zone in tunneling due to blasting damage. Simulation model is established and numerical simulation is made by means of threedimensional numerical software FLAC 3D. Firstly, the threedimensional stress redistribution and plasticized zone development are analyzed, assuming no blasting damage; Then, blasting damage is introduced; Finally, comparison and contrast is made between the simulation result of stress redistribution and plasticized zone development under nondamage condition and that under damage condition, and the influence of the blasting damage on the stress redistribution and plasticized zone development is summarized.