Interferometry is one of the most effective methods in measurement science, and whether it is to increase the dynamic measurement range or to detect high frequency error of surface, it is limited to spatial bandwidth of detection. So the relationship between bandwidth of interference fringes and frequency spectrum of wave-front is becoming the focus of attention, and it is analyzed and simulated based on the Fourier optics theory. The results indicate that, the spatial spectrum of interference fringes intensity is the expansion of the frequency of wave-front distribution function. And the extent of the expansion is determined by the amplitude frequency product of the wavefront. With the increase of amplitude frequency product of the wave-front, the bandwidth of interference fringes will be greater. According to the CCD resolution, the total bandwidth of interference patterns can be determined, and then the maximum spatial frequency of wave-front can be obtained. That provides a theoretical quantitative basis for the spectral characteristics of the interference methods, the optimal allocation of bandwidth and the increase of dynamic measurement range.