为了分析光轴在单块晶体加工过程中镜面失谐的自洽特征，建立了非平面环形腔镜面倾斜的数学模型，利用增广的光线矩阵讨论了光轴变动。结论显示：当存在距离误差时，不会影响光轴闭合；当输入输出耦合面设计成曲面时，能实现光轴自洽闭合；当它为平面时，静态分析表明，如果两个对称全反面的失谐角度满足特定关系，能再次实现光轴的闭合。如果失谐角度不满足对应关系，对称失谐和减小失谐量能减小耦合点偏离距离。动态分析过程则给出了一个更加合理的分析加工容差方法，同时为实验的调光过程提供了理论指导。

In order to analyze the self-consistence characteristics of optical-axis perturbation due to the manufacturing error of monolithic crystal, mathematical model for the mirror tilt of the non-planar ring cavity has been developed and optical-axis perturbation is discussed by utilizing the augmented ray matrix formulation. The results show that: self-consistence of the optical-axis is not sensitive to distance deviation and it can be realized by designing the input-output coupling mirror to be a curved surface. Static analysis indicates that the optical-axis is still self-consistent for the plane input-output coupling mirror when the angles of two symmetric totally reflective planes satisfy the certain relationship. Besides, if the certain condition of the angles cannot be satisfied, steps to reduce the deviation of coupling point position are considered from aspects of making manufacturing error symmetrical and decreasing error. At last, dynamic analysis provides a much more reasonable method to explore the manufacturing tolerance, offering a theoretical guide for the experiment.