A set of WCE optical system is designed for visible light imaging.the system adopts the optical structure of reverse distance and uses 4 lenses in total.Two Forbes aspherical surfaces are introduced to improve the overall performance of the system and to achieve miniaturization of the instrument.The field angle of the system is 150°,the relative aperture is 1/3,the diameter of the pupil is 0.35mm,and the total length is 8.3mm.The modulation transfer function curves of each field of view are higher than 0.6 at the Nyquist frequency of 143lp/mm with a higher resolution.The spot diagram of each field of view is almost within the Airy disk. Aberrations such as coma,astigmatism,field curvature,aberration and chromatic aberration have also been well corrected.The imaging quality is better,which can meet the requirements of WCE optical system.