18 groups of orthogonal experiments were designed for CMT seam welding of 3.0 mm and 2.5 mm thick Q345NQR2 weathering steel sheets. Eight typical positions of 18 groups of welding experiments were measured by 3D scanner

and the absolute deformation of each point was analyzed

and the optimal welding point with the largest deformation was point 5 at the end of the welding. The deformation of plate in clamping and releasing state is analyzed and the deformation law of clamping and releasing is obtained. The deformation of the plate was analyzed with the parameters of feeding speed of 7.0 m/min

welding speed of 0.42 m/min

welding gap of 1.5 mm

air supply speed of 20 L/min and arc length modified of-30%. The spatial deformation rule of the plate was obtained

which provides important reference for welding deformation control.