Abstract: The novel process of hydrogen-based shaft furnace (HSF) had attracted much attention owing to its significant reduction in CO2 emission. The interaction of H2 and CO with Fe3O4(111) surface (Fetet1-terminated and Feoct2-terminated) under the HSF conditions was researched using density functional theory method in this study. It was indicated that the H2 molecule would be adsorbed onto Fetet1-terminated surface with an adsorption energy (AE) of -1.36 eV, whereas the CO molecule preferred to adsorb on Feoct2-terminated surface with AE of -1.56 eV. Both the reactions for H2 and CO, corresponding to energy barriers of 0.83 eV and 2.23 eV, were likely to occur on the Fetet1-terminated surface. H2 reacted more readily with Fe3O4 than that of CO kinetically. As for the thermodynamics at 400-1400 K, the H2 was easy to adsorb, while the CO would like to react on the Fetet1-terminated surface. And these thermodynamically tendencies were reversed on the Feoct2-terminated in contrast. The disadvantage from thermodynamics in the reaction of H2 on the Fetet1-terminated surface could be offset more or less as increased temperature. Furthermore, the co-adsorption of H2 and CO on Fetet1-terminated surface were competitive, while those adsorption on Feoct2-terminated surface were synergistic. Therefore, the iron ores with a higher proportion of the Fetet1-terminated surface would be applied for HSF process. Together with the elevating reduction temperature and the increasing ratio of H2 in the reducing gas would promote the HSF efficient smelting. All of these findings provided the valuable guidance for optimizing the practical operation parameters and advancing the development of HSF process.