大相对孔径宽视场成像光谱仪已成航天、航空遥感的迫切需求，要求其望远镜具有大相对孔径、宽视场和像方远心、成像质量高等特点.以同轴三反望远镜的几何成像理论为基础，研究了大相对孔径、宽视场远心离轴三反望远镜的光学设计问题，并且编制了初始结构计算程序.采用视场离轴方式设计了一个波段范围200～1 000 nm，焦距210 mm，相对孔径1∶2.5，线视场14°的远心离轴三反望远镜，主镜和三镜为6次非球面，次镜为二次曲面.点列图直径的均方根值小于16 μm，80%的能量集中在一个像元以内，在奈奎斯特空间频率22.2 lp/mm处，调制传递函数大于0.75，畸变小于0.2%，各项指标均满足应用要求.

Space and airborne remote sensing urgently require large relative aperture and wide fieldofview imaging spectrometer. Its telescope must have large relative aperture, wide field of view, telecentric image space, and high image quality. Based on the geometric imaging theory of commonaxis threemirror systems, the design problem of large relative aperture, wide fieldofview, telecentric offaxis threemirror anastigmatic (TMA) telescope are studied. The procedure for calculating initial structural parameter is programmed. By means of field of view offaxis, an telecentric offaxis threemirror telescope system is designed. The spectral range is 200～1 000 nm, the focal length is 210 mm, the relative aperture is 1∶2.5, and the field of view is 14°. The primary mirror and third mirror are sixorder aspheric surfaces, and the second mirror is a quadratic surface. RMS diameter of the spot diagram is less than 16 μm, 80% of the enclosed energy is in a pixel, the MTF is more than 0.75 at Nyquist spatial frequency 22.2 lp/mm, the distortion is less than 0.2%, and each specification satisfy the application requirement.