Aiming at the problem of high tolerance sensitivity and difficult adjustment of 30 times continuous zoom TV,the effects of eccentricity on the MTF (modulation transfer function) of the optical system were analyzed by opticalsoftware. The results show that the central error of the front mirror group is sensitive to the asymmetric aberration. Inthis paper, the structural form of the spacer ring machine program is optimized, so that the lower surface of the lensis automatically centering. As the moving component of the system, both zoom lens group and compensation lensgroup are the key factors affecting the system image quality during the zooming process. In this paper, mechanicalcentering tooling is used to make the central axis of the moving assembly parallel to the axis of the guide rod. Theoptical axis of all components is corrected by the optical axis of the front mirror group. The optical system is preciselyadjusted, and the optical resolution of the small field of view reaches 2.43″, which is close to the limit of diffractionresolution.