River channel sludge cleaning bucket

The utility model relates to the technical field of dredging buckets, and discloses a dredging bucket for cleaning sludge in a river channel, arm power shafts are mounted at the corner ends of arm rods of two groups of rotating arms, two groups of connecting arms are sleeved at the shaft rod ends of each group of arm power shafts, and the output ends of two adjacent connecting arms are connected with a hydraulic support rod; and two grab buckets are symmetrically mounted at the bottom ends of arm rods of the two rotating arms, and self-drainage mechanisms are mounted at involution ports of the two grab buckets correspondingly. After the grab bucket is closed to dig riverway sludge, the compressed air bag in contact with the sludge in the self-drainage mechanism is compressed under the extrusion of heavy pressure of the sludge, and the opening and closing push plate is pushed to the drainage port to seal the drainage port, so that the sludge is prevented from laterally flowing and leaking; and the pressure is