在平行光路中，光学系统的光学元件的误差或微量运动可抽象为绕定点的微量转动，其成像关系可归结为在微量转动下物像共轭关系的依次迭代，利用光学系统这种动态成像关系的思想，建立一个统一的光学调整及误差分析的数学模型。利用此模型分析光通信系统中分光系统的机械安装误差对系统的影响，建立每个反射镜的机械调整坐标，从理论上指导分光系统中每个反射镜的机械调整，最终使通信激光发射系统和精信标激光接收系统的光轴平行度达到5″。

In collimating beam optical path, the error or minor movement of optical elements in optical system could be taken as minor rotation about a fixed point. The imaging relationship could be summarized as iterations of conjugating relationship between object and image in turn. The mathematical model of optical alignment and error analysis is built from the dynamic imaging method. The effect of beam splitter alignment error on optical communication system is analyzed with this model. The mechanical alignment of beam splitter system is theoretically supported with dynamic coordinate of every mirror. The axes parallelism between laser transmitting system and beacon receiving system reaches 5" after alignment.