Abstract: In wide angle reflection/refraction seismic sounding data processing, filtering and denoising methods based on Fourier transform and wavelet denoising method are still used. In view of the problem that there are inherent defects using the Fourier transform to process non-steady state seismic signal and that there not are the orthogonality, tight branch, and symmetry in wavelet transform at the same time, multi-wavelet denoising method is given, which has orthogonality, symmetry, compact, and overcomes the defect of traditional wavelet. Graphical user interface software is written based on the multi-wavelet in this paper. The software can show quickly and easily wide angle reflection/refraction seismic record section, can do adaptive threshold denoising in the multi-wavelet domain. Examples show that the methods and software in this paper are effective and feasible.