This paper discusses in detail the working principles of the micro-servomechanism for the system of measurement and compensation for the linear moving error of a precise lathe. The parameters of the micro-servomechanism by optimal design are also presented in it. An active circuit for high-votage discharge in the electrical driving source has been designed to accelerate the electrostrictive ceramal 481AQI's discharge for improving the system's frequency response. Finally，the static and dynamic machematical model of the system is established in this paper.