用二维快速傅立叶变化方法处理干涉图时，由于采样的数据序列长度必须是2的n次，故须将干涉图的数据范围圆形域延拓成矩形区域，文中提出了一种基于块重建算法的干涉图延拓的原理和方法，利用该方法对一幅实际干涉图进行了延拓，结果表明，该原理方法具有较高的处理精度，为波面相位复原奠定了基础。-Two-dimensional fast Fourier transform method for interferogram processing, due to the sampling of the data sequence length must be 2 n times, so the range of data required to interferogram Extension circular region into a rectangular area, the paper proposes a reconstruction based on block interferogram algorithm principles and methods of extension, the use of this method was a practical extension interferogram, the results show that the principle method has a high processing precision, the wavefront phase recovery basis.