Stepper motor stepper motor is a kind of induction motor, its working principle is the use of electronic circuit, direct current (dc) into time-sharing power supply, multiphase sequential control current, for stepper motor with the current power supply, stepper motor abilities to work properly, is time-sharing power supply for step motor drive, multiphase timing control device. Although the stepper motor has been widely used, but the step motor and not like a normal dc motor, ac motor under normal use. It has to be made by double annular pulse signal and power drive circuit and so on control system before use. So good with step motor is not easy, it involves the mechanical, electrical, electronic and computer and many other professional knowledge. Stepper motor as the performance of the component, is one of the key products of electromechanical integration, widely used in all kinds of automation control system. With the development of microelectronics and computer technology, increasing demand for stepper motor, has already come into common use in various fields of national economy. Stepper motor efficiency slightly higher than the induction motor is just common sense, both in the difference of efficiency is not very big, because there is a certain difference in power between them, so users tend to model selection of the motor according to the power to determine what motor, such as more than 2000 kw motor selection, the user generally consider to choose stepper motor. Stepper motor power, of course, a little higher than asynchronous motor, is not good, due to differences in this aspect, also because of stepping type motor have exciting winding and the slip rings, need operation workers had a higher level to control excitation. In using a temporary moreover asynchronous motor to realize free maintenance, but the use of stepper motor, but there will be a lot of maintenance work need us. This is how the working efficiency of the stepper motor is introduced, considering the various aspects of application situation, for below 2500 kw electric motor, asynchronous motor is still choose to use, because in such a level of the power, the asynchronous motor and stepping motor in power differences are not obvious. The computer if the power of the motor is very big, we still is to adopt stepper motor.