Step motor is a kind of open-loop control element step motor which transforms electric pulse signal into angular displacement or linear displacement. In the case of no overload, the rotation speed and position of the motor only depend on the frequency and number of pulses of the pulse signal, and are not affected by the load change. When the step driver receives a pulse signal, it drives the step motor to rotate a fixed angle according to the set direction, which is called "step angle". Its rotation is run step by step with a fixed angle. The angular displacement can be controlled by controlling the number of pulses, so as to achieve the purpose of accurate positioning; at the same time, the speed and acceleration of motor rotation can be controlled by pulse frequency, so as to achieve the purpose of speed regulation.
Stepping motor is a kind of induction motor. Its working principle is to use electronic circuit to supply power when DC is changed into component, and control current in multi-phase sequence. If this current is used to supply power for stepping motor, stepping motor can work normally. Driver is to supply power for stepping motor in time, and multi-phase sequence controller.

Although stepper motor has been widely used, but stepper motor is not like the common DC motor, AC motor in the conventional use. It can only be used by the control system composed of double ring pulse signal and power drive circuit. Therefore, it is not easy to use stepping motor well. It involves many professional knowledge such as machinery, motor, electronics and computer. As an executive component, stepping motor is one of the key products of mechatronics, which is widely used in various automatic control systems. With the development of microelectronics and computer technology, the demand of stepping motor is increasing day by day, and it has been applied in various fields of national economy.