Based on the SDS-3 E-beam lithography machine,the electrostatic deflection of the folded plate structure was used instead of the electrostatic deflection of the plate.The requirements that the electron trajectories and potential distribution must realize for electrostatic deflection of folded plate sturcture were discussed.The relationship between electrostatic deflection of folded plate sensitivity and potential distribution along axis was also derived.The aberration equations and aberration coefficients of electrostatic deflection were given.The electron trajectories and parameters were described in the vector form,the aberrations and structure equation were described in the integral form.Aberration coefficients are appropriate for computer aided design.Superior to the electrostatic deflection of the old plate,folded one is used in aberration.Finally,calculative data and More stripe patterns of the folded plate and plate were given.