Abstract: The cement industry is widely recognized as one of the foremost contributors to global carbon dioxide emissions, accounting for roughly 8% of the total worldwide output. Consequently, mitigating carbon dioxide emissions throughout the cement production process is a critical prerequisite for achieving sustainable development in the industry. Oxy-fuel combustion technology, recognized as one of the foremost carbon capture methods in the industrial kiln sector, can significantly reduce carbon dioxide emissions during the combustion process. Currently, both domestic and international researchers have predominantly focused on the pulverized coal oxy-fuel combustion in cement rotary kilns under O₂/N₂ atmospheres. In order to investigate the combustion characteristics of pulverized coal under O₂/CO₂ atmospheres, a computational fluid dynamics （CFD） approach was employed, using a cement rotary kiln with dimensions of ϕ4.8 m × 72 m as the study model to examine the impact of varying oxygen concentrations on the coal combustion process. The results indicate that when the oxygen concentration is increased from 24% to 36%, the flow field within the cement rotary kiln remains largely unchanged, exhibiting an overall “stick” structure, with both a central recirculation zone and an outer recirculation zone forming in the vicinity of the burner. The ignition of the pulverized coal gradually migrates toward the burner head, with the maximum temperature increasing from 1785 K to 2 026 K and the average temperature rising from 1385 K to 1412 K. Concurrently, the high-temperature zone expands while the overall flame length diminishes. When the oxygen concentration is between 27% and 33%, it can meet the actual production needs of cement rotary kilns. Simultaneously, due to the increased rate of carbon gasification, the CO generation rate accelerates, however, the CO production in cement rotary kiln gradually decreases. The higher temperature also enhances the reduction of NO_x by carbon particles, HCN, and NH₃, resulting in a gradual decrease in the NO_x concentration at the outlet, from 0.0549% to 0.0483%. Taking into account the practical production requirements of the rotary kiln, the cost of oxygen production, and NO_x emissions, it is recommended that the oxygen concentration for pulverized coal oxy-fuel combustion in a cement rotary kiln under O₂/CO₂ atmospheres should not exceed 33%.