针对高功率激光装置所需的大口径光学元件，进行了小工具数控抛光中频误差控制工艺研究。对数控加工过程中卷积效应对中频误差的影响进行分析，并建立了残余误差分析模型，对卷积效应所引入的残余误差进行定量分析。利用该模型对中频误差修正工艺参数进行了仿真分析，并进行了修正工艺参数实验验证，确定了全面匀滑最优化参数。在最优化工艺参数的基础上，针对大口径光学元件开展了数控抛光中频误差控制工艺实验验证，使400 mm口径平面窗口元件加工精度达到透射波前PV值为0.27λ，透射波前PSD1 RMS值为1.67 nm。该实验结果表明，通过400 mm口径平面窗口元件的中频PSD1控制技术研究，使窗口元件能够达到高功率激光装置对中频PSD1的指标要求。

For large optics of high-power laser facility, the controlling technology of mid-spatial frequency error is developed. Firstly, the CCOS convolution residual error caused by regular path is analyzed, and the residual error model is established. And then, the optimization parameters for controlling mid-spatial frequency error are achieved by this model. Finally, according to the optimization parameters, the mid-spatial frequency error of 400 mm aperture window is remarkably improved. After several CCOS iteration, the peak-to-valley(PV) is 170.856 nm, the root-mean-square(RMS) of PSD1 is 1.67 nm and no obvious mid-spatial frequency error is found. The result shows that the mid-spatial frequency error of 400 mm aperture window is under control, and the 400 mm aperture windows can be achieved and meet the requirement of mid-spatial frequency error in high-power laser facility.