The device combines infrared sensing technology, signal processing technology, communication control technology, computer technology and mechanical transmission technology organically to automatically monitor the fire in the protection range all-weather. In the event of a fire, the device starts immediately, carries out a horizontal one-dimensional scan of the fire source, determines the orientation of the fire source, the central controller issues an instruction, sends out a fire signal, starts the water pump at the same time, and opens the valve. The fire extinguishing device aims at the fire source to extinguish the water. After the fire source is extinguished, the central controller issues instructions to stop the water injection. If there is a new fire source, the fire extinguishing device will repeat the above process and return to the monitoring state after all the fire sources have been extinguished. The water jet form of the device is sector water jet, which not only has strong fire extinguishing ability, but also has certain ability to prevent fire spread.