Dredging device and dredging ship

The utility model provides a dredging device. The dredging device comprises a drill bit, a pipe body, a drill rod and a rotary driving piece, the interior of the pipe body is divided into an extraction cavity and a conveying cavity through a partition part, the extraction cavity is communicated with the extraction pipe, the conveying cavity is communicated with the water injection pipe, the drill rod and the pipe body are coaxially arranged, the drill rod is rotationally arranged on the partition part, the output end of the rotary driving part is connected with the upper end of the drill rod, and the drill bit is connected with the lower end of the drill rod. The dredging device can directly go deep into a target layer to conduct dredging, sediment on the upper layer does not need to be removed, damage to undisturbed soil on the surface layer of the water bottom is reduced to the maximum extent, and stable balance of an ecological system is maintained. The utility model further provides a dredging ship compri