Heat exchange plate laser stitch welding device and method

The invention relates to the technical field of laser welding, and provides a heat exchange plate laser stitch welding device and a method, wherein the heat exchange plate laser stitch welding device comprises a workbench, a laser welding head and a gas protection device, and further comprises a cooling bottom plate, two pressing beams and two pressing wheels, the pressing beams are arranged in parallel, the cooling bottom plate is provided with a water cold device, the two pressing beams are alternately arranged along a Y shaft, and can be used to press/loosen two heat exchange plates, the two pressing wheels are respectively arranged on the two sides of the laser welding head and are closely pressed on the two heat exchange plates, pressing positions of the two pressing wheels are arranged between the two pressing beams, and the two pressing wheels and the laser welding head synchronously move in the direction of the Y shaft when welding. The heat exchange plate laser stitch welding device and the method can fully guarantee gaps not to have between the two heat exchange plates by matching the two pressing beams and the two pressing wheels, enables the heat exchange plates below the two pressing beams to perfectly fit with the cooling bottom plate, and prevents the heat exchange plates from plumping up and deforming to affect welding quality during the welding process. Simultaneously, the water cold device which is arranged on the cooling bottom plate can rapidly bring away heat which is produced during the welding process, and reduces deformation of the heat exchange plates.