针对采用单点金刚石超精加工的KDP晶体光学表面，研究了切削参数对微观形貌频率特征的影响。通过功率谱密度获得表面轮廓频率分布，并用连续小波重构加工过程中随切削用量变化的微观轮廓频率特征。结果表明：切削参数对微观形貌的影响具体表现在实际频率特征上,中频特征波长及幅值反映了切深及转速变化，随切深及转速增加，幅值变大；低频特征反映了进给量变化，随着进给量变小，频率及幅值变小；高频特征是加工过程中振动及材料各向异性的具体表现。

The influence of cutting parameters on the frequency characteristics of optical crystal surface has been studied. The experiment of single point diamond turning was adopted to process KDP crystal. The frequency distribution of surface profile was obtained by power spectral density. The continuous wavelet method was used to evaluate the influence of cutting depth, feed rate and spindle speed on machined surface. The results show that the frequency characteristics reflect the effects of cutting parameters on surface topography. The wavelength and amplitude of mid frequency embody the change of cutting depth and spindle speed, and the amplitude increases with the increase of cutting depth and speed. Low frequency reflects the change of feed rate, and the amplitude becomes small as feed rate decreases. High frequency is the manifestation of vibration and material anisotropy in processing. Therefore the analysis of frequency characteristics on surface topography provides a reference for selecting the optimal process parameters.