：离轴三反光学系统具有成像质量高、可实现大视场、无遮拦等优点，但其装调难度大，镜面支撑结构质量大。为解决这些问题，基于三级像差理论，研究一种主镜、三镜可集成一体化的大视场离轴三反光学系统，并以焦距为1 200 mm，F数为12，视场为10°×1°的光学系统为例进行了验证设计。结果表明：调制传递函数接近衍射极限，视场内平均波像差RMS值为λ/55，最大波像差RMS值为λ/22。设计结果显示，光学系统装调自由度由12个减少到6个，可使光机系统可得到简化，实现了主三镜一体化设计。

Off-axis three-mirror system(OTMS) has the advantage of high image quality, large field of view and non-obscuration. But drawbacks also exist, such as the alignment difficulty, cost and large optomechanical weight. In order to solve these problems, the design of a novel OTMS was necessary. In this design, the primary mirror and tertiary mirror can be integrated on a single substrate based on third-order aberration theory. An example which has a focal length of 1 200 mm，F-number of 12 and field of view of 10°×1° was given. The mean WFE rms was λ/55, and the maximum WFE rms was λ/22. The result of this design shows that the number of alignment freedoms was reduced from 12 to 6, the weight of the mirror support assembly also can be lighter.