The utility model discloses a brushing device for a submerged structure. The brushing device is provided with a frame, wherein a first sealed cabin and a second sealed cabin are arranged in the inner chamber of the frame, the first sealed cabin is fixed at the front part of the inner chamber of the frame, and the second sealed cabin is fixed at the rear part of the inner chamber of the frame; the two corners of a front frame are provided with back propellers, the two corners of a rear frame are provided with back propellers and the middle parts of a lower left cross beam and a lower right cross beam of the frame are provided with power propellers; the middle part of the upper cross beam of the front frame is provided with a front camera, a first short connecting support is provided with a middle camera, and two side-by-side brushing mechanisms are arranged below the front part of the middle camera. According to the brushing device, by adopting dual sealed cabins, the isolation of the interference of electronic devices can be realized; meanwhile, the buoyant centre and center of gravity of the whole brushing device can be adjusted by adjusting the positions of the first sealed cabin and the second sealed cabin; furthermore, the defects including cracks on the surface of a building can be displayed by the middle camera, so that the surface of a dam can be shot better.