<p>This study investigates penetration explosion damage and subsequent discharge flow in high-arch dams under high reservoir water levels. Indoor model tests were conducted to analyze the damage process at vulnerable dam sections. A three-dimensional peridynamics model was developed to simulate the dynamic damage evolution in concrete structures under penetration explosion. The results demonstrate that peridynamics effectively captures both damage evolution and structural failure processes in rock-like media under explosive loading. Furthermore, computational fluid dynamics (CFD) simulations were employed to analyze discharge flow patterns through the damaged sections, elucidating scouring mechanisms on the dam foundation and body. The study reveals rapid flow field changes in the reservoir and quantifies the impact of water discharge following penetration explosion damage.</p>