The invention discloses a double-curved-surface stirring aerator, which comprises a main beam, a motor, a speed reducer, a fan, a gas pipe, a base, a hollow transmission shaft, a double-curved-surface stirring impeller and a crushing grid plate, wherein the base is fixedly connected in a through hole of the main beam; the speed reducer is fixed above the base; a transition pipe shaft, a hollow positioning shaft and a motor output gear are arranged in the speed reducer; the hollow positioning shaft is fixedly connected with the power output gear; the hollow transmission shaft is fixedly connected in the inner cavity of the hollow positioning shaft; the lower end of the transition pipe shaft is positioned in the inner cavity of the hollow transmission shaft; the top end of the transition pipe shaft is connected with one end of the gas pipe; the gas pipe is fixedly connected with the air outlet of the fan; the double-curved-surface stirring impeller is fixedly connected to the lower end of the hollow transmission shaft; the upper surface of the double-curved-surface stirring impeller is provided with stirring blades; and the lower surface of the double-curved-surface stirring impeller is provided with aeration blades. In an aerobic process in sewage treatment, the double-curved-surface stirring aerator can be used for providing stirring and aerating effects, and contributes to reducing sewage treatment cost.