Dredger: Hydraulic cutter suction dredger uses the rotary cutter head in the front of the suction pipe to cut and stir the solids in the river bottom. In this process the slurry concentration will reach a satisfactory ratio so that the powerful pump could suck and discharge the mixed slurry to the designated location bydischarge pipe. The series of cutting, suction, transporting and discharging actions could be finished continuously one time.