Abstract: The working principle of the automatic laser tracking transducer for welding will be described in the present work. This transducer is not restricted by the roughness of the detected surface by using the non-contact distance-detecting technique for the optical path of the direct-visual transverse focusing alignment. It can be used even to detect the uneven surface which was sheared, planed and manually gas cut. This transducer can be assembled into the single or double as required. The double receiver has various recepting combinations. By means of recepting signal of these combinations about 30 deviational positions of butt weld groove can be detected. Above-mentioned transducer can directly track the beveled sides, the edge of weld groove as well as the artificial tracking line (plastic tape). Aforesaid transducer has been applied in production.