Under the background of "double carbon", the development of low-carbon iron-making technology is an inevitable trend for low-carbon transformation for China's iron and steel enterprises. Based on the analysis of the utilization of coke oven gas and the current situation of gas-based direct reduction technology in China, a rational layout on metallurgical processes of long and short process based on coke oven gas balance is proposed by establishing a balance model of coke oven gas within iron and steel enterprises, with a view to developing direct reduction iron-making technology through rational utilization of coke oven gas and to providing solutions for carbon reduction in metallurgical processes. Meanwhile, an iron and steel enterprise with an annual output of 5×10⁶ t of molten iron in blast furnace is taken as an example, and according to the calculation on coke oven gas balance model, the surplus coke oven gas can meet the gas demand of direct reduction iron production line of the 1×10⁶ t, and the crushed coke produced by coking can provide 42.0 kg of coke powder per ton of sinter, which basically meet the fuel demand for sintering. In addition, under the new mode that combines long process and short process, the CO₂ emission per ton of steel is reduced to 1193 kg, and the carbon reduction ratio is as high as 30.32%.