Abstract: Active magnetic bearing (AMB) is an new-type bearing in which the rotor is suspended in the air gap between it and stator by the controllable electromagnetic force provided by electromagnets and rotates frictionlessly. Describes its construction and operating principle. To gain high-precision control, a mathematical model of AMB is developed with a design scheme given for the hardwares/softwares of AMB control system using DSP (digital signal processor) TMS320 F2812. Discusses the principle of PID (proportional-integral-differential) control of variable parameters with a simulation done to investigate the control scheme of the experimental setup designed. The simulation results showed that the digital control system of AMB has such advantages as high stability, fast response, small even no overshoot and high control precision, thus meeting the requirements of AMB control performance.