Position correcting system of welding robot

The invention discloses a visual system of a welding robot capable of automatically correcting position deviation of a welding gun. Before the first work piece is welded, a welding plane and a visual plane are subjected to parallel measurement by a laser ranging sensor, thus the position of the visual plane is adjusted to be parallel with the welding plane. Then, the placing position of the work piece is obtained by an industrial camera and precise demonstration operation is performed on the first work piece. Subsequent work pieces are welded in an identical way and the position of the welding gun is adjusted based on the deviation information obtained through images taken by the industrial camera. Therefore, a problem that an original demonstration program cannot work due to position deviation of the work pieces is solved, repeated demonstration operation is avoided, and working efficiency is improved greatly.