The invention provides a sector ejection fire extinguishing device. The sector ejection fire extinguishing device comprises a shell, a water intake pipe, a regulating mechanism, a sprayer and an inductor; the water intake pipe is contained in the shell, one end of the water intake pipe penetrates through the shell, and the other end of the water intake pipe is communicated with the sprayer; the sprayer extends out of the shell; the inductor is arranged on the side edge of the sprayer; the regulating mechanism comprises a supporting plate, a driving element, a gear component as well as a connecting sleeve; the supporting plate and the shell are fixedly connected, and the supporting plate is sleeved on the water intake pipe; the driving element is fixedly arranged on the supporting plate, and drives the gear component to rotate, and the gear component drives the connecting sleeve to rotate relative to the water intake pipe; the sprayer is fixedly connected with the connecting sleeve, and is provided with an arc surface; water ejection holes are formed in the arc surface; a water outlet of the water pipe aligns at the center of the arc surface; the water ejection holes are formed at one side of the center, and the opening widths of the water ejection holes at the center toward the outer side increase gradually. The sector ejection fire extinguishing device provided by the invention ejects water uniformly, ejects water in a sector shape in water type, is wider in water ejection range, and has a good fire extinguishing effect.