Now more commonly used the stepper motor including a reactive type stepping motor, permanent magnet stepper motor, hybrid stepping motor and single-phase stepping motor. The reaction stepping motor rotor magnetic circuit made of soft magnetic material, with the multi phase exciting winding, the magnetic conductance changes to produce torque. At this stage, reaction stepping motor for most applications.Stepper motors and General Motors differ mainly lies in its pulse drive form, it is this characteristic, the stepper motor can be and modern digital control technique. But the stepper motor in the control precision, the speed range, low-speed performance is inferior to conventional closed loop control of DC servo motor. The accuracy is not in need of special high occasions can use the stepper motor, stepper motor can exert its simple structure, high reliability and low cost characteristics. The use of the appropriate time, even with the DC servo motor performance comparable to.Stepper motor is widely applied in the production practice fields. Its largest application is in the manufacture of CNC machine tools, because the stepping motor does not require A / D conversion, can be directly digital pulse signals into angular displacement, so it is considered ideal NC machine tool components. Early stepping motor output torque is relatively small, can not meet the need, in use and hydraulic torque amplifier with a hydraulic pulse motor. With the development of technology of stepper motor, stepper motor has been able to separate in the system to use, has become an irreplaceable executive element. Such as stepping motor used in CNC milling machine feed servo drive motor, in this application, the stepper motor can be simultaneously completed two work, one of which is the torque transmission, the transmission of information. The stepper motor can also be used as CNC worm wheel gear grinding machine drive motor synchronous system. In addition to the application of NC machine tool, a stepping motor and can also be used on other machines, such as automatic feeding machine motor, as universal floppy drive motor, but also can be used in printers and plotters.Stepping motor with its remarkable characteristics, in the era of digital manufacturing plays a major use. With the different digital technology development as well as the stepping motor itself technology improves, the stepping motor will be applied in more and more fields.