Abstract: In this paper, Hilbert Huang transform (HHT) method is used to reduce vortex flow meter signal noise in oscillatory flow. The empirical mode decomposition (EMD)-scales filtering is used to erase vortex flow signal noise in oscillatory flow, and then the denoising effect of EMD-scales filter is compared with that of wavelet threshold filter using vortex flow meter signal noise in oscillatory flow. The signal simulation test shows that both EMD-scales filtering and wavelet threshold filtering can achieve good results, however, the former is more convenient and completely adaptive.