阐述了Golay3望远镜系统入射光瞳的结构与主镜F数的关系，通过入瞳函数推导出子镜具有倾斜误差的系统点扩展函数(PSF)和调制传递函数(MTF)表达形式，利用Matlab软件模拟了子镜倾斜误差对系统PSF和MTF的影响。利用Zemax软件设计了Golay3望远镜系统，通过对系统中子镜引入倾斜误差得到了系统的PSF和MTF并与上述理论模拟结果进行了比较。以标准鉴别率板为物体进行模拟成像，分析了倾斜误差对望远镜成像性能的影响。设计结果表明：理论模拟和实例设计的PSF和MTF对倾斜误差的反应一致且比较敏感；当倾斜误差引起的波面倾斜峰谷值变化达到一个波长时，PSF和MTF的主瓣和旁瓣均发生较明显的变化，变化的方向取决于引入倾斜误差的子镜位置；而当波面倾斜峰谷值变化超过一个波长时，PSF和MTF的变化趋势基本保持不变；成像结果表明随着水平方向上的子镜倾斜误差的增加，鉴别率板竖直方向上可分辨的最大线对数变化明显。

The relation between structure of entrance pupil of Golay3 telescope system and F-number of primary mirror is analyzed. Point spread function (PSF) and modulation transfer function (MTF) of telescope system are derived through entrance pupil function which considers the tilt error of one submirror; The effect of tilt error on PSF and MTF is simulated by Matlab program; a example of Golay3 telescope is designed by Zemax software, the PSF and MTF of the system are obtained with tilt error in a submirror, and compared with the theoretical simulation results. Finally, Golay3 telescope′s imaging capability is evaluated under different tilt error value with a standard board as the object. According to the result of the Zemax software, the change of both PSF and MTF of Golay3 telescope system because of tilt error is consistent with that of the theoretical simulation. When the peak-to-valley value of tilt wavefront is smaller than one wavelength, both the main lobe and the side lobes of PSF and MTF pattern vary enormously, the direction of the variation depends on the position of the submirror with tilt error. When the peak-to-valley value of tilt wavefront exceeds one wavelength, both the PSF and MTF remain unchanged basically. The imaging results show that with the increase of tilt error of the submirror in x direction, the maximal recognizable line pairs in y direction changes dramatically.