The invention discloses a sewage mixing and treatment device, which comprises a tank body, a plurality of racks, a push plate, a bracket, a power unit, a plurality of mixing parts and a plurality of feeding mechanisms; a guide rail is arranged on the tank body and is arranged along the length direction of the tank body; the plurality of racks are all mounted on the tank body, and the racks are arranged along the length direction of the tank body; the bracket is slidably mounted on the guide rail; the power unit is used for driving the bracket to move along the length direction of the guide rail; the plurality of mixing parts and the plurality of racks are in one-to-one correspondence, each mixing part comprises a stirring shaft, a gear and stirring blades, and the stirring shaft is vertically mounted on the bracket in a rotating manner; the gears are arranged on the stirring shafts, the gears are matched with the racks, the racks are located at the first moving paths of the gears, and when the gears move along the first moving paths and contact with the racks, the racks drive the gears to rotate; the stirring blades are mounted on the stirring shafts.