The invention relates to a rotary ball-throwing fire extinguisher. The fire extinguisher comprises a base, a motor, a gun barrel and a cartridge, wherein the motor is fixed on the base, and the vertically upward top end of a rotating shaft of the motor is vertically and fixedly connected with the bottom surface of the gun barrel; a gun barrel shell is of a barrel body structure with an upper opening, a spiral partition plate is arranged in the gun barrel shell, the cartridge is installed in the innermost layer of the spiral partition plate, and an opening is formed in the surface wall, corresponding to the outermost layer of the spiral partition plate, of the gun barrel; the root part of the cartridge is of a vertical cylindrical structure, the top of the cartridge is of a funnel-shaped storage bin structure, a bottom opening is vertically communicated with the central part of the gun barrel, and water bombs are assembled in the cartridge; and the motor, a smoke sensing switch and a storage battery form a circuit, and the smoke sensing switch is installed on the side surface of the base. The fire extinguisher has the advantages of reasonability in design, convenience, practicability, large fire extinguishment scope and the like.