The S500-G point-type smoke detector is equipped with an internal smoke fire sensor component. The sensor transmits the fire smoke signals detected to the microprocessor inside the detector. The microprocessor performs preliminary screening and processing of the collected signals to eliminate the influence of environmental interference, and then transmits the signals to the fire alarm controller for comprehensive analysis and judgment to issue corresponding fire alarm and control signals. The detector is of electronic coding type, and its working mode can be set in the fire alarm controller. The detector has its own audible and visual alarm with a sound intensity of ≥ 85db, which can warn the specific location of the fire on the scene.