• Absidia spinosa, a filamentous fungus from coal mines, effectively inhibits coal spontaneous combustion by covering and repairing coal pores, reducing oxygen availability.
• The fungus significantly alters coal's active functional groups, increasing ignition temperature by 25.34 °C and reducing total heat release by ~32.58%.
• Genomic analysis reveals genes for oxygen consumption, small molecule degradation, and metabolic secretion, linking to coal decomposition pathways.
• This eco-friendly biological method offers a sustainable alternative to traditional physical and chemical fire prevention techniques in goaf areas.