Abstract: A binocular stereo vision with laser system was developed.Clear image of the welding seam was obtained,The difficult problem of the Feature Point Matching algorithm in stereo vision was solved with the structure laser.A programme to acquire and process image was developed by Visual C++.The 2D image coordinates of the seam feature and the character of the seam was obtained.An algorithm of 3D coordinates calculation method was proposed.It can reconstruct the 3D coordinates of the seam with the 2D image coordinates of the seam feature point and obtain precise information of the seam.The experiments of the reconstruction of typical seams were done.The results show that the accuracy of the seam reconstruction is very high.