The utility model discloses a gravity dam bank the choosing that the breach overflowed of passing the flood period, a class dissipation structure falls, the bank breach is arranged on the monolith on next -door neighbour one side river bank, set up plunge pool in bank breach low reaches, one side of plunge pool is the bank slope, the top on bank slope sets up the bank platform, the bank is led the wall paper and is put on the platform of bank, and link to each other with the bank breach is terminal, the bank platform passes through the bank slope and links to each other with plunge pool, the dividing pier is arranged and is being led the opposite side of the bank breach that the wall is relative with the bank, rivers turn up in being used for stoping the breach. The radius that the wall was led on the bank is 4H~6H, and the bank is led wall length and for 2H~4H, highly is greater than 0.4H, leads the wall angle of intersection terminal and the bank slope and is 5~15, the bank slope is greater than 1: 0.3 the plunge pool depth of water is greater than 0.2 DELTA Z, H is the highest the poor of water level and breach floor elevation of passing the flood period, and DELTA Z is the upper and lower potential difference of swiming of design. Do not set up packway on the bank slope. Energy dissipation effect is good, and the rivers flow state is good, and impact phenomenon is concentrated to no zigzag current phenomenon, nothing. A po is not washed away to the mainstream, and the bank velocity of flow is little. For conventional concrete, low in cost.