Abstract: In order to prevent coal spontaneous combustion, a new type mine fire extinguishing gel which consists of sodium carboxymethylcellulose, zirconium citrate and gluconic-δ-lactone has been developed. The gelation time of different ratios of gel components was tested and the optimum fire-extinguishing ratio suitable for coal mine under different conditions was determined. Then the water loss rate of the gel was tested, the results show that the gel has good thermal stability and strong water retention ability. The temperature-programming experiment shows that the addition of gel reduces the oxygen consumption rate and the production of CO during coal spontaneous combustion, which can suppress the oxidation process of coal. The influence of gel on coal activation energy was calculated and analyzed by thermogravimetric curves, the results show that the addition of gel increases the energy required for coal-oxygen reaction and increases the difficulty of the reaction. FTIR was also used introduced to analyze the effect of gel on active groups of coal during heating coal oxidation, the results show that the addition of the gel inhibits the conversion of C-H components to oxygen-containing functional groups, and reduces the number of active functional groups, inhibits the oxidation reaction of coal.