The invention provides a double-
beam laser arc composite single-surface horizontal position
welding method and device. The
welding method comprises the following steps: carrying out surface treatment on a
welding workpiece, and fixing the welding workpiece; arranging a double-
beam laser arc composite device and an air
injection device on the to-be-welded side of the welding workpiece; and setting
welding process parameters, starting the air
injection device and the double-
beam laser arc composite device, and carrying out horizontal position welding. A horizontal position welding device used in the welding method comprises a double-beam
laser arc composite device and an air
injection device. The double-beam
laser arc composite device comprises a TIG welding gun, a first
laser, a second laser and a GMAW welding gun which are sequentially arranged in the welding direction. The air injection device is placed on the side edge below the first laser device, and the flow and the direction of a sprayed
shielding gas can be adjusted. According to the welding method, the problems of incomplete fusion and
undercut of the side wall are solved, the
porosity of a welding seam is reduced, and the welding efficiency is improved.