针对大口径光学设备使用过程中因传感器靶面离焦导致的图像模糊问题，从图像复原方法入手，推导光学设备的离焦点扩散函数和离焦传递函数，提出图像离焦程度判断方法，运用爬山法、逆滤波方法，寻找最佳离焦量值和方向，复原模糊图像为清晰图像，给出了大口径光学设备的实时视频对焦方法,并进行实验验证。结果表明该方法在外场光学设备的自动调焦中具有重要的推广应用价值。

Aiming at the image blurring problem caused by defocusing of sensor target in the use of large-aperture optical equipment, from the image restoration method, the defocus diffusion function and defocus transfer function of optical equipment were deduced, the judgment method of image defocus degree was proposed, the mountain climbing and the inverse filtering method were used to find the best defocus value and direction and restore the blurred image into the clear image. The real-time video focusing method of large-aperture optical equipment was given and verified by experiments. The results show that this method has important promotion and application value in automatic focusing of the outfield optical equipment.