The invention discloses a full-automatic fire extinguishing purifying device and a use method thereof. The device comprises a water storage tank, a dry powder tank, a special extinguishing agent tank,a dust removal and harmful gas purifying system, an automatic tracking and positioning jet device, a dry powder electromagnetic nozzle, a smoke sensor, a flame sensor, a camera, an alarm device and amicro intelligent control system. All parts are connected through a wire, when the sensors detect abnormal environment related data, the intelligent control system controls the automatic tracking andpositioning jet device and the dust removal and harmful gas purifying system to be started, fire hidden dangers can be removed, smoke and harmful gas are purified, the dust removal and harmful gas purifying system can preliminarily filter large-particle pollutants contained in the smoke, and the smoke is subjected to deep purifying through a gas purifying chamber. The function of intelligently monitoring the environment where the device is located can be achieved, the automation degree is high, the device can be used for extinguishing different types of fires under different scenes, meanwhile, the fire smoke purifying function is achieved, and the practicability is high.