介绍了非稳定风载的功率谱，采用最小二乘法建立了光学元件的刚体位移与其镜面节点关系的线性表达式，并基于小位移假设线性化处理的方法推导出表征光学系统各光学元件刚体位移所引起像点偏移量的光学敏感度矩阵。进一步将这些线性关系式作为前处理导入望远镜结构有限元模型中，进行了频率响应分析。以不同风速和俯仰角组合共20种工况下非稳态风载的功率谱密度作为输入，得到了像点相对成像面横向偏移量的随机响应曲线。考虑主轴伺服控制系统和成像器件积分时间对像点偏移量的影响，对像点横向位移的随机响应曲线进行了修正，得出了像点随机偏移量引起的线扩散函数（LSF）和调制传递函数（MTF）衰减曲线，并计算得到20种工况下长曝光与短曝光成像时系统的斯特列尔比。结果表明，5等级风速下任意俯仰角和6、7等级风速下接近0°俯仰角的情况下光学系统的斯特列尔比大于0.8，望远镜系统可以正常工作；8等级风速任意俯仰角情况下系统的斯特列尔比都小于0.8，望远镜成像质量受到严重的影响，系统无法正常工作。

Power spectrum of the unsteady wind loads is describes in detail. The linear relationship between rigid displacement of the optical elements and specular node is built by the least squares method. And the optical sensitivity matrix characterizing the optical image point offset caused by a rigid displacement of the optical elements in the optical system is built based on the assumption of small displacement linearization method. Then, these linear relationships are imported into the finite element analysis model of the telescope system and the frequency response analysis of unsteady wind loads is proceeded. The random response curves of image point offset relative to the imaging surface are obtained from input of the power spectral density functions of unsteady wind loads under sixteen cases of different wind speeds and elevation angles. Finally, the random response curve of image point lateral displacement is corrected considering the impact of main axes servo control system and the integration time of imaging elements on image offset. And line spread function (LSF) and modulation transfer function (MTF) attenuation curves caused by the random offset are deduced. The Strehl Ratio of imaging system is calculated in sixteen cases in the short and long exposure time. The results show that the Strehl ratio of the optical system is greater than 0.8, when the telescope is located in fifth level wind under any elevation angle and in sixth and seventh levels wind under near 0° elevation angle. Under the above circumstance, the telescope system can work properly. While the Strehl ratio is less than 0.8, when the telescope is located in eight level wind under any elevation angle. In this case, the image quality of the telescope is seriously affected, so the system cannot work properly.