In order to study the damage effect of beam-slab piled wharf subjected to underwater explosion, model experiment and numerical simulation were conducted to study the damage characteristic of beam-slab piled wharf subjected to underwater explosion. The damage process and mechanism of the beam-slab piled wharf were analyzed in terms of shock wave and bubble pulse, which provided guidance for the further research in damage assessment and emergency repair of high-piled wharf. Results show that shock waves load and bubble expansion are important damage factors for piles. After flow and spike induced by bubble pulse are important damage factors for wharf upper structure. The middle and top of the piles and the connection of beams and panel are the main damage areas of high-piled wharf subjected to underwater explosion. A full-scaled numerical simulation study shows that the explosive depth has great influence on the failure mode and damage area of beam-slab piled wharf. As the explosive depth increases, the maximum horizontal deflection of piles increases first and then decreases, and the damage area moves down and the piles directly to the explosive is most seriously damaged. The horizontal deflection is maximum subjected to explosion in the middle of water. When the explosive explodes near the water surface, the wharf panel has a crack. The horizontal deflection of the piles has decreased by 75.77% compared to the explosion in the middle of water. When the explosive explodes near the water bottom, the bottom of piles is damaged and the wharf panel is not damaged. The maximum horizontal deflection of the piles is most widely distributed. The maximum deflection depth deviation of 4.18 times that of near water surface explosions, making damage investigation and repair more difficult.