Abstract: Three-dimensional stereo circuit can expand traditional two-dimensional integrated circuit into 3D dimensions, but its board shape design and component solder joint positioning become more and more flexibility and complexity. In order to reduce the labor cost in the process of 3D circuit and improve the processing efficiency, a binocular structured light system was designed for the solder joint positioning of welding machine. The system was arranged to locate solder joints of 3D circuit boards, and to solve the problems of coordinate conversion and solder joint recognition. Based on the cooperation of hardware and calculation software, the system was designed to complete the coordinate conversion simply between the binocular structured light system and the welding machine and to calculate the coordinate of circuit board soldering joints, substituting the complex process of manual measurement. Experiments show that the proposed solution possesses high operation accuracy and can meet the demand of component solder joint positioning in the welding machine.