The basic principle of linear stepper motor: using a screw and nut meshing, take some way to prevent the relative rotation of the screw nut, so that the screw axial movement. Generally speaking, there are two ways to achieve this transformation at present. The first way is to build a rotor with internal thread in the motor to achieve linear motion with the internal thread of the rotor meshing with the screw. The second way is to use the screw as the shaft of the motor to achieve linear motion through an external drive nut meshing with the screw outside the motor. Therefore, the design has been greatly simplified, making it possible in many applications to use linear stepper motors directly for precise linear motion without the installation of external mechanical linkages.