The invention discloses a petrochemical wastewater treatment sedimentation pool with high convenience in inner wall cleaning. The sedimentation pool comprises a sedimentation pool main body, wherein fixing plates are fixedly connected with the left and the right sides of the sedimentation pool main body; a supporting plate is fixedly connected with the top of each fixing plate; and the tops of thetwo supporting plates are fixedly connected through a connecting plate. The sedimentation pool provided by the invention has the advantages that through cooperation among the fixing plates, the supporting plates, the connecting plate, a cleaning motor, a cleaning rotating shaft, a first gear, a rolling bearing, a rotating shaft, a second gear, first cleaning rods, first cleaning plates, first scrapers, second cleaning rods, second cleaning plates, second scrapers, sludge discharging pipes, sludge discharging heads, sludge pumps and sludge removing pipes, the problem of the conventional petrochemical wastewater treatment sedimentation pool that cleaning of the inner walls is inconvenient is solved; and the inner walls are automatically cleaned, so that the labor intensity of workers is reduced, the cleaning efficiency is improved, and wastewater treatment is greatly facilitated.