Abstract: Based on the principle of “demand-supply” balance of mine air quantity，VOD (ventilation-on-demand) intelligent ventilation supplies air on demand，and it is the energy-saving intelligent ventilation technology of metal mine and can realize the closed loop control of fan and air quantity by remote centralized monitoring system.VOD intelligent ventilation analyzes the factors affecting the actual air quantity on demand from aspects of the distribution of working face′s type，the working status of main equipment，the type and number of operational staff，underground air temperature and humidity，and feed them back to the VOD intelligent ventilation control system with a certain means of monitoring.Then，the actual air quantity Q_x on demand will be automatically calculated.Accordingly，the actual air supply quantity is monitored through the air monitoring technology and feed back to the VOD intelligent ventilation control system to calculate the actual air supply quantity Q_g.According to the value of Q_x and Q_g，automatical regulation of the fan can be controlled by the start-stop or the frequency conversion to realize the closed loop control of fan and air quantity in ventilation system.At the same time，3D ventilation simulation system provides a reference for the fan control decision-making of VOD intelligent ventilation control system.Both of them can also verify with each other.

Key words: VOD intelligent ventilation, Personnel (device) positioning system, Ventilation monitoring, 3D ventilation simulation