A 3D reconstruction method based on linear-structured light stripe and binocular vision is proposed. The key points are extracted by the contour curvature, and are used to extract the normal vector of the contour. With the characteristics of the skewness of the distribution, the stripe center is extracted based on the barycenter method. The 3D reconstruction process is finished while the image coordinate of the welding seam are transformed to the word coordinate. The experimental results show that this method is quick and accurate, and is suitable for the requirements of the structure light welding system.