Abstract: In view of problems of complex ventilation system, difficult management and adjustment of ventilation system according to experience existed in Sitai Mine, Ventsim 3D ventilation simulation system was applied to build 3D ventilation network model, which could reflect status of ventilation system in Sitai Mine. The system realizes functions of ventilation simulation, pollutant simulation, thermal simulation, fire simulation, economy simulation and provides decision basis for management and optimization of ventilation system.