The invention discloses a steel heat-insulation fireproof door leaf. The steel heat-insulation fireproof door leaf comprises a door leaf body, wherein the door leaf body comprises a frame and a steelskin, and a filling cavity is formed between the frame and the steel
skin; a
steam generation mechanism comprises a
water storage tank, heat conduction fins are arranged outside the
water storage tank, the heat conduction fins are connected with the
water storage tank and the
metal skin, the
water storage tank is connected with an air guide
pipe, and an air guide one-way valve is arranged on the air guide
pipe; a pressurizing spraying mechanism comprises a pressurizing cylinder; a
piston body is connected in the pressurizing cylinder in a sealing and sliding mode; the
piston body divides the pressurizing cylinder into an upper cavity and a lower cavity, the upper cavity communicates with the air guide
pipe; the lower cavity is filled with fire extinguishing liquid; the lower cavity is connected with a high-pressure hose; a
pressure release valve is arranged on the high-pressure hose; the high-pressure hose is connected with a front flow dividing pipe and a rear flow dividing pipe; andthe front flow dividing pipe and the rear flow dividing pipe are connected with a water mist spray head correspondingly. According to the arrangement, when a fire source approaches the door leaf, corresponding fire extinguishing operation can be automatically carried out, the temperature around the door leaf is reduced, and therefore good heat insulation and fireproof effects are achieved.