Abstract: A new technology was proposed to control residual distortion of thin-plate weldments with rotating extrusion.Extrusion force with is exerted by rotary action of an extrusion head on weld and zone near the weld to form the tensile plastic strain, which can counteract the welding-induced residual compressive plastic strain, and reduce or even eliminate the welding residual distortion.The surface of weld processed by this method is flat and smooth, and the stress concentration in theweld is decreased obviously.Experimental results showed that this technology can decrease the welding residual distortion of thin-plate weldments to below 3% of that of conventional weldments.The control effect of welding residual distortion has relation to some technical parameters.A good control effect of welding distortion can be acquired only when all kinds of technological parameters are matched properly.