<p>Welding residual stress significantly impacts fatigue and stability in engineering applications. The vibratory stress relief (VSR) treatment offers an efficient and flexible method for releasing residual stress, particularly in welded structural components. This research investigates how VSR treatment influences the residual stress and impact toughness in welded joints of Q235 steel. VSR treatment was applied to Q235 steel specimens, and Charpy impact tests were performed on them both with and without the treatment. Scanning electron microscopy (SEM) was used to analyze the fracture morphology of the welded joints, and the Vickers microhardness of Q235 steel-welded joints was tested with and without VSR treatment. With the help of ABAQUS finite element software, a numerical model for Q235 steel welding was set up, and the effect of VSR on residual stress was analyzed in combination with residual stress measurements by the hole-drilling method. Research indicates that VSR treatment enhances the impact toughness of welded joints by 36.04% compared to untreated samples, with a notable decrease in residual stress levels, thereby reducing stress concentration effects. Fracture morphology and residual stress simulations confirm that VSR treatment homogenizes internal stress and significantly improves impact toughness.</p>