Abstract: As the depth of mine excavation increases， ventilation shifts from an easy to a challenging phase. To address potential issues of high temperature and low airflow in the underground working face of Yanqianshan Iron Mine， 2 optimization plans were proposed with the -269 m level as the research subject. A 3 D visualization simulation model of the underground ventilation system was created， and mine ventilation system network analysis software was used for 3 D simulation and network calculations to simulate and analyze the optimization plans. Numerical simulation results of the optimized ventilation system showed that Plan 1 increased the average airflow in the northern area of the -269 m roadway by 1.13 m³/s and decreased the temperature by an average of 0.14 ℃. Plan 2 increased the overall airflow in the -269 m roadway by an average of 5.51 m³/s， with a temperature reduction of 0.34 ℃ in most roadways near the mining area. A comparison indicates that Plan 2 provided a greater increase in airflow and a wider impact range for temperature reduction. Both plans improved the ventilation system， offering valuable reference for optimizing underground ventilation systems in most domestic underground mines.