从断裂力学的角度进行分析，在考察断裂强度的基础上，对机载多光谱相机光学窗口的厚度进行了详细的设计。相关分析解决了光学窗口厚度的工程设计问题，使光学窗口的设计更加合理可靠。同时，结合窗口工作环境，利用有限元方法计算其稳态温度场分布，再结合分析结果中的温度载荷和相关的广义力载荷，计算光学窗口在力热耦合情况下玻璃表面的变形。利用Zernike多项式对最终变形值进行拟合，得到变形后的光学窗口面形，输入到Zemax软件中，以波像差和调制传递函数(MTF)作为光学系统成像质量评价指标，分析了在这种工作环境下光学窗口变形对多光谱相机光学性能的影响。结果表明，在已知的环境条件下，窗口变形对系统成像质量的影响可以忽略。

Based on the fracture mechanics analysis, the glass thickness of the optical window of an airborne multi-spectral camera is designed in detail. Correlation analyses solve the engineering design problems of the optical window thickness and ensure the design more reasonable and reliable. Considering the complex environment, steady-state temperature field is calculated by means of finite element method. Linking temperature load to generalized force load, the deformation of optical window under the structure-thermal coupling condition is calculated. Optical window surface after deformation are derived by fitting the final deformation value using Zernike polynomial fitting. Fitting coefficients as the input of Zemax, the impact of the deformation of the optical window on the optical performance of multi-spectral camera is analyzed by means of wavefront error and modulaiton transfer function (MTF) as a measurement of imaging quality. The result shows that based on the known operational environment, the impact on imaging quality of optical system is negligible.