The invention discloses a mine liquid nitrogen fireproof and fire extinguishing device, which comprises a liquid nitrogen cylinder tank car, a main pipeline, a low-temperature liquid pump and a liquid nitrogen gasification device, wherein one end of the main pipeline is connected with the liquid nitrogen cylinder tank car, a first supply pipeline is connected onto the other end of the main pipeline, the input end of the low-temperature liquid pump is connected onto the main pipeline, the output end of the low-temperature liquid pump is also connected with a second supply pipeline, the pipeline main body part of the second supply pipeline is positioned in the liquid nitrogen gasification device, the tail end of the second supply pipeline extends out of the liquid nitrogen gasification device, an exhaust fan used for lowering the temperature of the pipeline main body part is arranged on the liquid nitrogen gasification device, a first control valve is arranged on the first supply pipeline, a second control valve is arranged on the second supply pipeline, and a main control valve is arranged on the main pipeline. The invention also discloses a use method of the mine liquid nitrogen fireproof and fire extinguishing device for fireproof and fire extinguishing purposes.