Abstract: In this paper, the gel material and the other solid-liquid two-state fire-extinguishing materials for comparative analysis are added by adding the best proportion of yellow mud slurry to the same amount of coal samples, and then according to the mechanism of coal spontaneous combustion and related physical and chemical principles. The relevant data were calculated and processed by computer, and the changes of relevant parameters in the spontaneous combustion test results of coal samples were compared. The best proportion of yellow mud slurry added gel materials and other solid-liquid fire-extinguishing materials were investigated to inhibit the spontaneous combustion of coal. The difference is verified by its ability to suppress the spontaneous combustion effect of coal.