In this paper, watant role in the signal processing. Analyzing the limitations of Fourier transform in the signal processing, this article reflects the superiority of the wavelet transform, analyzes the principle of Mallat wavelet transform, builds decomposition and reconstruction model of Mallat wavelet, and introduces the SURF threshold to improve Mallat transform method. Finally, comparing the denoising results of single Mallat and improved Mallat, the paper verifies that the improved Mallat method is feasible.