The invention provides a spraying and stirring device of an agent for black river sewage treatment. The spraying and stirring device comprises a filter screen cartridge, a head cover, a screw, an agent delivery tube, a motor, an electric cylinder, a piston 1, a piston 2 and a water tank, wherein the screw is assembled at the rear end of the motor, the screw is arranged inside the filter screen cartridge, and the agent delivery tube is arranged at front end of the filter screen cartridge. The design realizes sufficient contact between medicine powder and medicine liquid; the agent delivery tubeis arranged on upper side of the screw, the electric cylinder is assembled on left wall of inside of a main body, the piston 1 is arranged at the right end of the electric cylinder, the piston 1 is arranged at the right end of the main body, the piston 1 is assembled at the left end of the water tank, the piston 2 is assembled at the upper end of the piston 1, the piston 2 is arranged on the water tank, and the water tank is arranged at the right end of the main body. The design realizes control and observation of medicine dosage. The spraying and stirring device of the agent for black riversewage treatment is convenient to use and operate, good in stability and strong in use effect.