Abstract: In order to enhance the fire prevention property of the gel, using chitosan (CS), acrylamide (AM), and N,N ' -methylene bisacrylamide (MBA) as the base materials, a physical - chemical cross - linked Al³⁺ - CS / PAM - MBA double network gel was prepared. The chemical network formed by the covalent bond cross-linked of polyacrylamide (PAM) and MBA was used as the first network, and the second network was formed by the ionic bond cross-linked of chitosan molecules and Al³⁺. The optimal ratio of the gel was optimized by testing the gel formation time and viscosity of the gel. The fire prevention property of gel was studied by thermal stability analysis, temperature programmed experiment, infrared spectroscopy, thermal analysis and fire extinguishing experiment. The results show that Al³⁺ - CS / PAM-MBA double network gel has good thermal stability and good effect of spontaneous combustion inhibition. It can effectively inhibit coal spontaneous combustion oxidation. This gel can inhibit the process of the coal-oxygen reaction by destroying the functional groups closely related to it, which makes the coal oxygen reaction more difficult to carry out, thus playing a role in inhibiting coal spontaneous combustion. The fire extinguishing test further indicated that the gel had a significant inhibitory effect on the spontaneous combustion of coal. After the addition of the gel, the temperature of the coal dropped rapidly, and no re-ignition phenomenon occurred.