详细描述了光阑在主反射镜前的无光焦度校正板－牛顿光学系统的设计方法。通过移动光阑位置，改变主镜偏心率，选择校正板光焦度，进行光学系统的光线计算，求解出光学系统的最佳选择，并给出各种设计曲线和设计结果，对光学系统进行合理的评价。并以通光口径Φ=300，相对孔径A=1／2，视场角θ=士5°，校正板光焦度■₁₁=5的牛顿光学系统为例，分析得到系统优化后的像差系数S1=0．000002λ，S₂=0．000025λ，0°视场时的波像差为0．3174λ，±5°视场时的波像差为90．9861λ。

The design method of a Newton optical system with a zero-power corrector,where the stop is before the primary mirror,is discussed in detail. By moving the stop,changing the eccentricity of primary mirror,selecting the power of the corrector,and calculating the rays of the system concerned,the optimized optical system solution is obtained,various design curves and results are given,and the optical system is evaluated. Take Newton optical system for an example,where the clear aperture Φ is 300,relative aperture A is 1/2,field of view θ is ±5°,the corrector's power ■₁₁ is 5,its aberration coefficients S₁ can achieve 0.000002λ,S₂ is 0.000025λ after optimization,the wavefront aberration is 0.3174λ at 0° field of view,and 90.9861λ at ±5° field of view.