A multi-stage atomization type two-phase flow water mist generation device for controlling a coal field fire is suitable for managing a coal-rock cavity high-temperature zone in a large-area coal field fire zone.The device comprises a pressure water supply pipe, a multi-hole nozzle and a jet flow atomization barrel.An impact atomization chamber, a mixing acceleration chamber and a diffusion jet chamber are arranged in the jet flow atomization barrel in sequence.The end, close to the multi-hole nozzle, of the impact atomization chamber is provided with a hemispheric inner wall, and the inner wall is provided with a slant conical air suction hole so that the impact atomization chamber can be communicated with the external environment.Pressure water supplied by the pressure water supply pipe is preliminarily atomized through the multi-hole nozzle; external air is automatically sucked into the impact atomization chamber under negative pressure generated by jet flow of the nozzle to collide with mist flow formed in preliminary atomization, and secondary atomization is achieved; then, the mist flow and the air are further mixed and rubbed in the mixing acceleration chamber, and atomization is performed again; then, the atomized water is jetted to a coal field fire control zone through the diffusion jet chamber.The device does not need an additional compressed air system and is compact and simple in structure, safe, reliable, easy to operate, high in portability and high in atomization degree.