The work aims to study the damage effect of reinforced concrete prestressed T-beam bridge under different attack modes, so as to provide reference for the damage assessment and attack decision-making. The damage effect of a reinforced concrete prestressed T-beam bridge under 3 attack modes of aerial explosion, contact explosion and semi enclosed space explosion of ammunition was studied through numerical simulation. The damage modes of reinforced concrete prestressed T-beam bridge under different attach modes were quite different. Aerial explosion and contact explosion mainly caused perforation and plastic deformation damage to the bridge deck. While, semi enclosed space explosion mainly caused layered cracking to the bridge deck and bulging deformation and concrete collapse to the web and crossbeam. Damage effect of the T-beam bridge in semi enclosed space explosion is better than that in aerial explosion or contact explosion.