Abstract: Combining VSR(Vibratory Stress Relief) effects in material stress relief and experimental stresses re-distribution in the aluminum alloy thick-plate after VSR, VSR plays a limited role in the thick-plate structural residual stresses relaxation. But energy analysis in dislocation theory proves that VSR has certain effect in stress relief of stress concentration regions caused by material internal micro-structure defects. Under conditions of certain excitation frequency and excitation time, VSR can homogenize the intra-plate stresses since micro-yield of material local regions reduces residual stress level in the micro-regions. Experimental results of surface stresses and shape dimensional stability in thick-plate show that VSR has obvious effects in stabling shape and relaxing surface residual stresses with a great gradient.