提出了借助于傅里叶变换提取叠栅条纹相位分布的途径来获得条纹微小位移量的方法中 ,图像的截断必然会产生频谱泄漏 ,从而引入数据处理的误差。详细分析了傅里叶变换中频谱泄漏产生的原因及其对测量误差的影响 ,提出了图像处理时 ,通过外插值将截断区域延拓为叠栅条纹周期整数倍时可以减小甚至忽略频谱泄漏所引起的相位计算误差 ,并对此进行了数值模拟以及初步的实验验证 ,证实了该方法的有效性 ,为叠栅偏折法应用于微细尺度流动与传热的实验研究提供了有效的技术途径 The method of obtaining the small displacement of fringes by means of Fourier transform to extract the phase distribution of moire fringes will inevitably cause spectral leakage and lead to the error of data processing. The reason of spectrum leakage in Fourier transform and its influence on measurement error are analyzed in detail. When the image processing is extended, the extension of the truncated region into an integer multiple of the moire period can reduce or neglect the spectrum leakage The calculated phase error caused by this method is simulated by numerical simulation and preliminary experimental verification. The validity of this method is verified. It provides an effective technique for the experimental study of the application of the stack grid deflection method in the micro-scale flow and heat transfer way