Abstract: In order to solve the problem that the conventional Doppler estimation method of single carrier frequency domain equalization system is not accurate or high complexity is required for high-precision estimation, a Doppler estimation algorithm based on complex autocorrelation amplitude and phase information of velocity measurement signal is proposed in this paper. Firstly, the amplitude information is used to complete the Doppler rough estimation, and the rough estimation results are used to solve the ambiguous problem of the phase method, so as to obtain high-precision Doppler estimation results. Simulation results show that the proposed algorithm has high Doppler estimation accuracy and low computational complexity. The lake test data analysis results show that in the scenario of communication distance of 2 km, bit rate of 5 kbit/s and speed of 3 m/s, the proposed Doppler estimation method is capable of providing high-precision Doppler estimation results and significantly improving the bit error rate performance compared with the conventional methods.