Abstract: Since a zero-power corrector itself has no achromatic aberration and Petzval curvature, and has such variables as curvature PW, powers φ11 and φ12, etc, it makes the correction of the aberrations of an optical system easier. A Newton optical system with a zero-power corrector, whose stop is before the primary mirror, is proposed. The parameters of the system are the clear aperture Φ=300mm, relative aperture A＝1/2, stop position lp2/f=-0.75, and the eccentricity of the primary mirror e2=0. Based on the ray calculation, aberration analysis and optimization of the optical system, the corrector lens optimal power φ11＝5, and the optimized on-axis wavefront aberration W＝0.0001λ were obtained.