In the machinery manufacturing industry, the measurement results of the size parameters of a workpiece are related to the material use rate and the working performance of the equipment, which has important practical significance. This study proposes a vision measurement method for workpieces based on binocular vision and line-structured light. First, the line-structured light and binocular vision are used to obtain the spatial point cloud of the target surface, and a shortest path search algorithm for the surface distance between any two points based on the spatial point cloud is designed. Then, the geodesic distance measurement results are optimized through surface reconstruction and partial projection. The results reveal that the range of the noncontact measurement is within 100?620 mm, and experiments show that the relative error does not exceed 0.70% compared with manual measurement. This method is expected to be applied to noncontact distance measurements on the surface of a medium-sized workpiece.