5-Hydroxymethylfurfural is a crucial platform molecule derived from biomass, and its selective conversion to furan chemicals holds significant importance for the high-value utilization of biomass. In this study, acid-modified coal fly ash was used as a support for non-precious metal cobalt to prepare a novel catalyst (Co/CFA), which demonstrated excellent performance in the selective hydrodeoxygenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran. By investigating the catalyst preparation conditions, it was found that with a 30wt% cobalt loading, the selectivity of 2,5-dimethylfuran can reach 98.1 %, and the conversion of 5-hydroxymethylfurfural is 99.0 %. A series of characterization showed that the acid modification treatment increased the pore structure and specific surface area of the coal fly ash, was conducive to the dispersion of cobalt, and improved the activity of the Co/CFA catalyst. This innovative approach harnesses the potential of waste materials, emphasizing resource efficiency and sustainability in catalyst development.