Abstract: To address the issues of central air duct wear and poor low-load combustion stability performance present in the new type of low-NO_x axial swirl burner (the burner before optimization is referred to as the original burner), the central air structure of the burner was eliminated (the burner after optimization is referred to as the optimized burner). Laboratory 1∶4 cold-state single-phase modeling experiments were conducted on above two types of burners to investigate the impact of the presence or absence of the central air structure on the outlet flow field of the burner. Meanwhile, industrial experiments were carried out on a 350 MW opposed-firing boiler burning bituminous coal that employed these two types of burners. Results show that both the original burner and the optimized burner form an annular recirculation zone at the burner outlet, while the recirculation zone area of the optimized burner is larger. The height of the recirculation zone increases from 0.07 m (0.2d, where d is the flared diameter of the outer secondary air) to 0.1 m (0.28d), representing a 43% increase in height. The ignition distance of the optimized burner is approximately 1 m, while that of the original burner is approximately 1.15 m. The optimized burner experiences earlier ignition, with O₂ content decreasing and CO being generated earlier and faster.