To solve the problem of welding of fi llet welds with leg in one pass of more than 6...8 mm due to the draining of metal from vertical wall it is proposed to use two-electrode welding. The computer analysis of this process showed that acceptable formation of the fi llet weld can be achieved by optimizing of the welding process parameters, including the positioning of electrodes relative to the weld. Due to this, it is possible to provide leg of welds upon welding up to 12 mm. However, large legs of fi llet welds in twin-arc submerged arc welding can be obtained only if the distance between the arcs is suffi cient in order to form separate weld pools, and one of the arcs will be shifted by leg half on the vertical wall.