Abstract: A fast digit-reversal permutation algorithm for the radix-B fast Fourier transforms (FFT) is presented in this paper, which decreases the computation of the "digit-reversing" and speeds up the FFT by loop nesting dividing the datas into small groups. According to timing experiments, the fast permutation algorithm significantly hastens the digit-reversal permutation and saves the FFT running time by 1.3%~4%,which is 7%~19% shorter than that of other permutation algorithm.