Welding method and welding system

The invention provides a welding method and a welding system.The welding method is used for welding a longitudinal seam of a roller and comprises the steps that the roller is placed at a welding station, and the roller is adjusted to enable the longitudinal seam of the roller to extend in the X-axis direction; moving the roller to align one end of the longitudinal seam with the positioning device of the welding station, and determining the welding starting position and the welding ending position of the longitudinal seam according to the relative position relation between the longitudinal seam of the roller and the positioning device and the length of the longitudinal seam; the welding gun is controlled to move to the welding starting position from the initial position; after the welding gun moves to the welding starting position, the welding gun is controlled to move from the welding starting position to the welding ending position in the X-axis direction at the preset speed, and the longitudinal seam is wel