Currently as a main way of piezoelectricity micro-feed implementation, PID control arithmetic often gives out the uncertainty in restraint of control object, and so that the precision and response speed cannot meet the use's needs. A new type of micro-feed control system in ultra-precision grinder is proposed, which makes up the disadvantage of traditional closed loop arithmetic in precision and response speed, obviously improves the slow-moving fallibility of piezoelectricity and creeping and sudden changing speed of workbench in machine tool, and has been successfully applied in process of ultra precision grinder. In processing experiment the novel system achieves less than 0.04 mu m in positioning accuracy, less than 80ms in response time, less than 0.02 mu m error in returning to zero point and has no phenomenon of creeping and sudden changing speed in machine tool. The system has lower cost; smaller cubage, higher reliability, better capacity of resisting disturbance and easiness in application.