The invention discloses a Kose quality flowmeter digital signal processing system based on AFF and SGA comprising signal conditioning circuit, A / D converter, digital signal processor (DSP), liquid crystal display (LCD) circuit, keyboard input circuit, digital / analog (D / A) converter, power amplifying circuit and software. The method uses multi-to-one filtration, adaptive funnel type filtration (AFF) and Sliding Goertzel Algorithm for sampled data processing, by calculating the fundamental frequency and phase of the flow tube vibration, the time difference between the frequency and two-way signal can be obtained from the phase differential, thus acquiring the mass flow value and the density value, an actuating signal is produced by the frequency value from the DSP calculation and sent to D / A for power magnification, making the flow tube vibrate.