The invention provides a mine goaf stopping agent rapid atomization fire-extinguishing device which comprises an atomizing device and a generating device; the atomizing device comprises atomizing nozzles, nitrogen injecting nozzles and a stopping agent nozzle; the atomizing device is mainly used for spraying atomized liquid nitrogen and stopping agent through the atomizing nozzles to enable the liquid nitrogen and the stopping agent to be uniformly sprayed out at the same time for performing fire extinguishing treatment on a coal body in a goaf; and the generating device is a common mine device and comprises a stopping agent generating device and a ground nitrogen producing unit. The invention further provides a using method for the device. The fire-extinguishing device provided by the invention can realize rapid acquisition of atomized and mixed liquid nitrogen and stopping agent when a fire disaster occurs in the goaf suddenly as well as rapid and efficient fire control on the emergency fire accidents in the goaf, so that the life and property safety is effectively guaranteed, the mining working efficiency and the mine benefit are improved, and the device can be popularized and used.