The key of Coriolis mass flowmeter signal processing depends on the accurate estimation of frequency and phase difference. Frequency estimation methods exists the problem of low tracking accuracy for a long time, and phase difference estimation methods exists the problems of insufficient accuracy and poor real-time performance. Firstly, by introducing negative feedback control, the problem of long-time continuous tracking for adaptive notch filter can be effectively solved and the accuracy of frequency estimation can be improved. Then, the frequency estimation results are used to process the whole period data of the enhanced signal filtered by the adaptive notch filter. Then, Hilbert transform is performed on the signal after the period data processing. Finally, the signals before and after Hilbert transform are correlated, and the phase difference can be obtained by sinusoidal formula, so as to obtain the mass flow. The simulation results show that the proposed method has high frequency and phase difference estimation accuracy, and can be used for real-time signal processing for Coriolis mass flowmeter.