介绍了一台口径为1.23 m光电望远镜的Coude光学系统，通过比较国内外地基大口径望远镜Coude光学系统的形式，结合实际情况，设计了以离轴非球面反射镜作为二次成像元件的Coude光学系统，并给出了相应的检测和装调的方法.经实际检测和装调对准后，对Coude光学系统的设计、检测和装调对准过程中的误差进行了分析和比较，证明了检测与装调方法的可靠性和先进性.该Coude光学系统的焦距为125 m，视场为1.5′，波段为0.4~5 μm，系统波像差优于λ/50(λ=0.632 8 μm)，实验室内检测波像差为λ/20.装调对准完成后对恒星观测，用ShackHartmann波前探测器测量其波前误差，得到整个望远镜Coude光学系统的波像差优于λ/4.

A 1.23 m aperture optical telescope and its Coude optical system were introduced. Compared several forms of Coude optical systems with internal and overseas groundbased telescope, a kind of optical system was designed that used offaxis elliptical mirror as reimaging element. Then the corresponding measurement and alignment methods of optical system were obtained. After actual measurement and alignment, the wavefront errors among three processes (designed errors, test error and alignment errors) were compared and analyzed, which proved that the method of measurement and alignment were reliable and advanced. The focal length of Coude optical system is 125 meters, field of view is 1.5′, the band of wavelength is between 0.4~5 μm, and the designed RMS wavefront error is less than λ/50(λ=0.632 8 μm). The RMS wavefront error that measured in the room is less than λ/20. The telescope was used to observe fixed star, the wavefront was tested with ShackHartmann wavefront sensor, and the whole Coude optical system RMS wavefront error of less than λ/4 was obtained.