Abstract: We put forward an edge detection approach based on 2-D wavelet in the paper.B-splines is an easiest function which has compact support and is efficient to put into practice via software and hardware,so we use B-splines wavelet to detect welding seam edge.In this paper,it is studied to process the same image with different directional wavelets and to have image wavelet transform at different scales.In the end we extract seam edge information.This approach can be used to process the larger visual range of information.