Abstract: In this paper, the preparation process of bentonite(BENT)/acrylamide（ＡＭ）/acrylic acid （ＡＡ） ternary copolymerized absorbent gel and its fire extinguishing performance were studied. The optimum gel matching ratio parameters were studied by orthogonal experiment and the fire extinguishing parameters of the gel were analyzed by using the programmed temperature experiment. The results showed that when the mass ratio of acrylamide/acrylic acid is 110%, the mass ratio of bentonite/acrylic acid is 10%, the mass ratio of boric acid/acrylic acid is 0.06%, the mass ratio of potassium persulfate/acrylic acid is 0.90%, neutralization degree is 80%, temperature is 90 ℃, a kind of high performance water-absorbing gel with the water absorption ratio of 1 011.5 was obtained. In the state of complete dehydration, when the water absorption of the gel is 250 ml/g to 550 ml/g, the inhibitor ratio can reach to 77%. Finally, based on the physical similarity simulation experiment of fire extinguishing in goaf, the fire extinguishing performance of water and gel was tested. The results show that the gel is more advantageous than water in the mine fire prevention.