The invention relates to an image processing mode for welding bead center tracking in a welding process. The image processing mode comprises the following steps of collecting an image of a welding bead in the welding process and identifying the image; establishing a coordinate system within a welding bead range needing to be identified, and identifying the boundary lines of the inner side and theouter side of the welding bead; grabbing two points on the boundary line of the outer side, separately making a vertical line to the boundary line of the inner side to obtain two vertical points, connecting two points at opposite corners to obtain a first intersection point, and repeating the operation to obtain a second intersection point; and connecting the first intersection point and the second intersection point to obtain a welding bead center line to be tracked, adjusting the horizontal position of a welding gun, and automatically tracking the obtained welding bead center line to enablethe welding bead to be in a center position. The image processing mode gets rid of dependence on welding operator experience and technologies; and through a driving machine head motor installed in thewelding gun, welding gun horizontal position adjustment is performed according to an image processing signal, and the obtained welding bead center line is automatically tracked, so that the welding gun is positioned in the welding bead center position.