Regarding the test object surface as scattering plane,and using spherical wave as reference wave,with different wavelength illumination,reconstruction position of object plane wave field is studied by using Angular spectrum theory.The result shows that,when the physical meaning of the image is not considered,diffraction image center reconstruction with S-FFT(Single Fourier Transform) is corresponding to the frequency spectrum center of object wave field.Taking the S-FFT reconstruction image as a reference,the location of the object wave field spectrum can be well determined,then the reconstruction field of different wavelength can be accurate overlapped with adjustable magnification reconstruction Angular spectrum method.