Abstract: Plate butt vibratory welding tests under different conditions were designed to investigate the influence of welding heat input and vibratory acceleration on welding residual stress.The results show that when the welding heat input is 22.8 kJ/cm,residual stress is reduced evidently as the acceleration increases.Residual stress is the lowest when the welding heat input is 26.6 kJ/cm and acceleration is 10 m/s².While as heat input increases to 31.6 kJ/cm,the residual stress distinctively decreases under the acceleration of 15 m/s².The direction of residual maximum main stress is proximately parallel to the welded seam.The reduction of transverse stress and minimum main stress at 15 m/s² compared with that at 0 m/s² is above 30% under three kinds of heat inputs.The effect of stress relief by vibration is evident.TEM results of the welds shows that density of dislocation is greatly reduced after vibration.