ABSTRACT A new type of biomass environmentally friendly hydrosol (DEP) was proposed to inhibit coal spontaneous combustion (CSC). The DEP consists of two parts, the PDopa side chain solution formed by the redox reaction of Dopa and EGCG and the main chain sol solution formed by the free radical polymerization of AA under the action of APS initiator. The −COOH, −NH2, and −OH in Dopa can be grafted onto the skeleton of the main chain via double strong hydrogen bonding interactions with the −COOH group in PAA to form a stable three-dimensional cross-linked network structure. DEP can inhibit CSC through three aspects: oxygen isolation, increasing the activation energy of coal oxidation, scavenging active groups and free radicals. The calculation simulation results show that EGCG in DEP can remove various active free radicals with lower activation energy at room temperature, breaking the chain cycle reaction of coal spontaneous combustion, which proves its high efficiency. This study provides a new way to apply mussel-inspired adhesion mechanisms to the prevention of CSC.