Abstract: Taking the actual sewage pipeline in the urban area of a county in southern China as the research object, the sedimentation status and sediment properties of sewage pipelines in the residential quarter and vegetable market in the urban area were determined. By comparing various dredging methods, the high-pressure water jet method was selected for silting removal. The new inflatable sewage pipe plugging device, washing-suction integrated vehicle and KEG Emperor spray head were used. The orthogonal test of nozzle outlet pressure and nozzle moving speed was carried out to compare the silting effect, oil consumption, water consumption, silting time and total cost, and the best silting parameters with high efficiency and low cost were selected. The results showed that the degree of sewage pipeline silting in the residential quarter was about 50%, and that in the vegetable market was about 40%-50%. The fluidity of sludge in pipelines of the residential quarter was better than that of the vegetable market. Lower pressure at the nozzle outlet could satisfy sludge cleaning. The optimum dredging parameters for sewage pipes in the residential quarter were spray head outlet pressure 9 MPa and spray head movement speed 0.3 m/s, and the optimum dredging parameters for sewage pipes in the vegetable market were spray head outlet pressure 12 MPa and spray head movement speed 0.3 m/s.