The motors of motorized spindles are all AC asynchronous induction motors, so when they are used in high-speed machining machines, the starting speed should be increased from static speed to tens of thousands or even hundreds of thousands of revolutions per minute, and the starting torque is large, so the starting current should exceed the rated current of ordinary motors by 5-7 times. The driving methods include inverter driving and vector control driver driving. The drive control characteristic of the inverter is constant torque drive, and the output power is proportional to the torque. The latest frequency converter of the machine tool adopts advanced transistor skills, which can realize stepless speed change of the main shaft. The drive control of the vector control driver of the machine tool is constant torque drive at the low speed end and constant power drive at the medium and high speed ends.