ABSTRACT To improve their whole-stage inhibition effects on the spontaneous combustion of coal, curcumin (CCM) and chitosan (CTS) were grafted, and the natural nanomaterial montmorillonite (MMT) was used for intercalation to prepare the composite gel inhibitor CTS-CCM/MMT. Its macro effect and micro mechanism of inhibition were studied. SEM analysis revealed a significant increase in the surface folds and pores of CTS-CCM, suggesting enhanced mechanical properties and thermal stability. XRD and DSC experiments demonstrated a reduction in the diffraction angle 2θ from 21.148° to 20.011° for CTS-CCM/MMT, along with a 21.3% increase in glass transition temperature. This supports the effective improvement of thermal stability through intercalation treatment. Thermogravimetric analysis indicated a higher characteristic temperature point for the inhibitor composite. Infrared diffuse reflection experiments showed deactivation of oxidation activity for the hydroxyl and aliphatic groups through combined inhibition treatment. These findings collectively suggest that the gel exhibits heightened stability and flame retardancy, and can effectively inhibit the entire spontaneous combustion reaction of coal.