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 3D visualization simulation model of the underground ventilation system was created,and mine ventilation system network analysis software was used for 3D 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.