Abstract: According to the current situation of main fan of No.2 mine in Inner Mongolia Energy Company, a monitoring system is built and put into operation, which is based on the communication function and takes the PLC controller as its core. The operation results show that the monitoring system can perfectly supervise, display and alarm the parameters and has the well functions of one-button operation, fault automatic switching. The application of the system realizes the online monitoring and automatic control of the main fan, improves the automatic management level of the main fan equipment, and effectively ensures the safe and reliable operation of the main fan equipment.