Abstract: Simulation research was carried out on a 1 780 m³ Hoogovens internal hot blast stove in Shougang using the CFD method. The research contents mainly include the flow status of air and gas in the rectangular burners before mixing, combustion status of mixture gas, concentration and temperature distributions in the combustion chamber, flame shape, and velocity and temperature distributions in the doom. The result shows that there is heterogeneity in some degree about flow filed in the air nozzle outlet and gas outlet. Along the width direction of the combustion chamber, the flame height changes greatly. A little carbon monoxide remains in the outlet of the doom. On the surface of the checker chamber, the velocity distribution of smoke is not uniform, and the maximum temperature difference is also very large.