Abstract: With the development of science and technology, coal mine belt machine driven by more traditional asynchronous motor is more and more replaced by permanent magnet synchronous frequency conversion direct drive system due to its low load rate, low motor efficiency and low power factors.It has the characteristics of large starting torque, high operation efficiency, wide overload capacity, energy saving and environmental protection, small volume area, light equipment weight and so on.Permanent magnet synchronous frequency conversion direct drive system provides convenience for operators.The equipment provides perfect protection function for the belt during operation.It has very high reliability performance, can accurately control frequency conversion, increase rich communication functions, and can adapt to work in harsh and extreme environment.Through the practice of permanent magnet synchronous direct drive frequency conversion system in Bulianta Coal Mine 106 main conveyor belt machine, it is proved that the permanent magnet synchronous direct drive frequency conversion system improves the motor driving mode and power parameters, prolonging the service life of the whole machine, reducing the damage and maintenance of equipment, reducing energy consumption, and bringing obvious economic benefits.