Abstract: Against the backdrop of "carbon neutrality", carbon reduction in the long-process steel production route based on blast furnace-converter (BF-BOF) has become a hot research topic in the iron and steel industry. The operational efficiency of ferrous material flow at the interfaces between ironmaking, steelmaking and rolling processes exerts an important influence on carbon reduction of the long-process steel production route, and interface technology has become one of the key research directions for carbon reduction in the long process. Taking the ironmaking-steelmaking interface based on torpedo ladle-hot metal ladle in a domestic steel plant as the research object, this paper constructed a simulation model for material flow operation at the ironmaking-steelmaking interface using Python tool, and systematically studied the influence of production organization modes such as torpedo ladle allocation under blast furnaces on the operational efficiency of material flow at the ironmaking-steelmaking interface, with torpedo ladle turnover rate, empty ladle time during turnover and total waiting time as evaluation indicators. The results show that the commissioning mode and operation mode of torpedo ladles have the most significant influence on the operational efficiency of material flow at the ironmaking-steelmaking interface; reducing the number of online turnover torpedo ladles from 18 to 17 increases the turnover rate by 3.0%-6.5%; compared with the turbulent flow operation mode, the torpedo ladle turnover rate is increased by about 20% under the laminar flow operation mode where 3 blast furnaces correspond to 5 converters at the ironmaking-steelmaking interface; under the "17+1" commissioning mode of torpedo ladles, reducing the number of torpedo ladles allocated under blast furnaces by 1 within the range of 6-10, increasing the ratio of "one torpedo ladle for one transfer" by 10% within the range of 80%-100%, and increasing the ratio of "one torpedo ladle to one hot metal ladle" by 10% within the range of 60%-100% improve the torpedo ladle turnover rate by 4.6%, 2.3% and 1.6% respectively. After optimizing the production organization mode of the studied ironmaking-steelmaking interface, the torpedo ladle turnover rate is increased from 5.2 times/d to 6.6 times/d, the temperature drop in the process from blast furnace tapping to hot metal entering the desulfurization station is reduced by 11 ℃, and the carbon emission(CO₂) per ton of steel in the whole process is reduced by about 3.3 kg. The research results can provide a reference for improving the operational efficiency of ironmaking-steelmaking interfaces in other domestic enterprises of the same type.