Abstract: In order to optimize the phase reconstruction algorithm, the distribution characteristics and spectral response of different filtering windows were analyzed for the Fourier spectrum of the wavefront interferogram. The optimal filtering window type of the fast Fourier transform (FFT) dynamic phase reconstruction algorithm was determined by computer simulation and experimental test. The residual error of the wavefront peak-valley value between the reconstructed wavefront by the simulated interferogramand the original wavefront is 0.008 5λ, as well as the residual of the wavefront root-mean-square is 0.000 1λ,while the residual of the wavefront peak-valley value between the obtained wavefront by the experimental interferogram and by the phase-shifting interferometry is 0.009 3λ, as well as the residual of the wavefront root-mean-square is 0.000 5λ. The results show that, after fitting the phase filtered and reconstructed by Hamming window, the residual surface error of the wavefront obtained is smaller that the reference wavefront, and the phase reconstruction accuracy is better than 0.01λ, which can be further applied to the measurement of large-caliber optical elements.