The 3D laser vision positioning system is composed of 3D laser, industrial personal computer and vision software. The robot carries the 3D laser to the designated position to take photos. The vision software performs image operation and sends the workpiece deviation value obtained to the robot, thus guiding the robot to accurately grab the workpiece after automatic deviation correction. The 3D laser supports 3D laser function and 2D photographing. The former is based on the trigonometric light sectioning. The linear laser beam is used to obtain the height, inclination and rotation of the feature under measurement, and the center of the feature is identified with the 2D photographing function, so that the deviation value of the whole workpiece relative to the standard part can be determined. The laser of the system only supports local imaging; therefore multiple sets of lasers will be needed. It is suitable for the material handling, grabbing and other project requirements of super-large workpieces (such as vehicle side wall parts) in various production lines.