Abstract: Coal spontaneous combustion poses a significant safety hazard during coal mining, leading not only to resource wastage and environmental pollution but also potentially triggering severe mine fire accidents. Additionally, the massive stockpiling of industrial solid wastes (e.g., fly ash and carbide slag) threatens the ecological environment. To solve the above problems, a new type of biological cementitious slurry for preventing and controlling coal spontaneous combustion was developed through the enzyme-induced carbonate precipitation (EICP) technology. This material uses the carbonates produced in the EICP process to cement industrial solid wastes such as fly ash and carbide slag, achieving the dual goals of highly effective prevention and control of coal spontaneous combustion and the resource utilization of solid wastes. Through multiple characterization techniques, including low-temperature nitrogen adsorption (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry-differential scanning calorimetry (TG-DSC), and temperature-programmed tests, the effects of different material ratios on the cementation performance and flame-retardant properties of the bio-cemented slurry were systematically investigated. Reveal the mechanism of action of using EICP technology in combination with fly ash and carbide slag for the prevention and control of coal spontaneous combustion. Laboratory-scale fire suppression simulation experiments were conducted to evaluate the extinguishing effectiveness of the bio-cemented slurry on burning coal. The products in the bio-cemented slurry are primarily calcite-type calcium carbonate, which, together with calcium hydroxide generated from the reaction between calcium oxide (main component of carbide slag) and water and fly ash particles, synergistically fills coal pores and forms a protective coating. The treated coal samples exhibited a significant reduction in pore volume, with macropores and mesopores decreasing by 46.38% and 40.28%, respectively. The crossing-point temperature of the treated coal increased by 21 °C, and the average flame-retardant efficiency reached 73.08%. Fire suppression tests demonstrated that the bio-cemented slurry effectively prevented coal re-ignition, exhibiting superior flame-retardant performance compared to water and other slurry materials.