波前功率谱密度（PSD）是反映高功率激光系统中光学元件中、高频信息的重要参数之一。介绍了利用波前位相信息计算功率谱密度的方法，提出对空域应用汉宁窗的方法抑制因波前数据的突然截断导致频域出现的吉布斯噪声。针对空域加汉宁窗后波前数据能量会因汉宁窗的权重变化而变化的情况，推导了加窗前后PSD的均方根(RMS)值间的比例关系。对高功率激光驱动器使用光学元件的PSD进行了计算，结果表明，采用汉宁窗的方法能抑制吉布斯噪声，通过数据修正的方法可修正汉宁窗的权重分布不同对PSD计算结果的影响。

The power spectrum density is widely used to specify the medium and high frequency of large aperture components. The numerical method for calculating power spectral density is introduced. As the left and right edges of wavefront data (or the top and bottom) are discontinuous one with another, which is usually the case with real data, these edges will introduce spurious noise in the spectrum when performing a Fourier transform. To lessen this effect, a Hanning window is used to reduce Gibb′s noise from edge discontinuities. Since the Hanning window is a weighting function, the relation between the calculated results with and without Hanning window are analyzed. The analyzing result shows that a constant of 3/8 should be used to modify the caculated result after applying Hanning window.