Abstract: Based on the research for the existing ventilation system of Jinshandian Iron Mine，the impacts on -340 m level due to the pollution air of -410 m level was simulated on the east stope multi-level mining.The 3D mine ventilation network model was established based on CFX and its accuracy was tested by the measured data.The ventilation of eastern-340 m level was improved by excavating and transforming the air shafts，increasing local fans and other measures，and the feasibility of the optimization scheme was judged by the simulation and analysis.The analysis of the wind speed and flow of mine air based on CFX provides scientific basis for the ventilation network optimization and design of ventilation system.

Key words: Ventilation network, Multi-level mining, CFX, Optimization scheme