Abstract: In order to prevent coal spontaneous combustion, a new kind of gel foam was prepared with sodium carboxymethyl cellulose (CMC), zirconium citrate (ZrCit), gluconate-δ-lactone (GDL) and compound foaming agent in a certain proportion. The basic performance tests of thermal stability, permeability and adhesion of the prepared gel foam were carried out respectively. TG experiment was used to study the influence of the coal sample treated with gel foam on the mass and heat of the coal sample compared with the raw coal sample during the heating process. Through the change of the concentration of the indicator gas CO of coal spontaneous combustion in the programmed temperature experiment, The retarding property of gel foam was investigated and the flame retardant mechanism of gel foam was analyzed based on the experimental results. The experimental study shows that the gel foam with high price Zr⁴⁺ as metal crosslinking agent has stable structure, can significantly enhance the thermal stability and water retention of the gel foam, make the coal oxidation heat loss significantly reduced in TG analysis, the maximum heat release power decreased by 19.9%, make the coal oxygen composite oxygen consumption rate and CO production rate decreased in the temperature program experiment, indicating that the gel foam can Coal spontaneous combustion can be effectively inhibited by physical and chemical reactions.