Abstract: MAG welding and laser-MAG hybrid welding process tests were carried out respectively for 4 mm and 8 mm thick Q345B test plates, the weld forming was analyzed and the macromorphology, tensile property and bending property of the welded joints were detected.The results show that compared with the conventional MAG welding, the laser-MAG hybrid welding can realize one-side welding and back side free forming without back plate, the welding speed is significantly improved and the welding efficiency is doubled; the consumption of welding materials is only about 22%-27% of that of MAG; the welding heat input is small, and the workpiece deformation after welding is significantly smaller; the tensile and bending properties of the welded joint are qualified and meet the requirements of practical engineering application.