Abstract: In this paper, based on correlation coefficient, a new algorithm is proposed to estimate the frequency of sinusoid signal. When the SNR of sinusoid signal is sufficient, the estimation error of the new algorithm is adjacent to the Cramer-Rao Low Bound. Compared with the improved Rife algorithm and the Iterative frequency estimation algorithm, although the accuracy of the new algorithm is lower, but computing speed is sufficient higher, so the new algorithm is quite use for the engineering.