Abstract: The main reason of deflection distortion in high resolution ligh luminance three tubes project TV is analyzed, and the basic theory for adjusting the scanning distortion is studied.The adjusting current which is used in convergence curcuit to adjust typical deflection distortion is presented in this paper.The developped convergence curcuit compensates misconvengence parts rapidly and can achieve good convergence within 0.5 scanning-line width everywhere in standard scanning (NTSC, PAL, SECAM).The convergence does not degarde the picture quality.