Abstract: The combustion performance of a built-in flue gas hot-blast stove sub-stoichiometric high-velocity burner with a load of 3 822 kW was investigated using the CFD (computational fluid dynamics) numerical simulation method. Based on the initial structure, a ceramic flame stabilizer rod with a diameter of 10 mm was added to the combustion chamber to enhance combustion stability. The effects of the gas nozzle spacing (31–70 mm), the number of circumferential nozzle groups (4–9 groups), and the combination methods of the flame stabilizer rod on the combustion performance were examined to optimize the structure. The results indicate that when the gas nozzle spacing is set at 62 mm, the number of circumferential nozzle groups is 5, and a cross-shaped flame stabilizer rod configuration is adopted, the mixing intensity between the fuel gas and combustion-supporting flue gas is significantly enhanced, leading to more complete combustion and improved flame stability. Compared with the initial structure, the optimized configuration increases the outlet temperature of sintered flue gas in the combustion chamber by 6.3% to 1,139.78 ℃, raises the flow velocity by 4.5% to 93.18 m/s, and reduces the CO mass fraction substantially by 70.8% to 0.0038. Through the comprehensive optimization mechanism where the flame is anchored by the stabilizer rod, turbulent mixing is enhanced by the nozzle arrangement, and flow resistance is controlled by swirl intensity, simultaneous improvements are achieved in combustion temperature, flow stability, and pollutant control efficiency.