Abstract: The vibratory stress relief (VSR) process works in a cyclic creepmechanism. To deal with the distortion in the welding of the HT-7U vacuum room,the residual stresses are eliminated in the welding place by aVSR process, to improve the size precision of the vacuum room. With anan analysis of dynamic stresses and the measurements ofresidual stresses before and after the VSR process, the reductionand redistribution of residual stresses can be evaluated. Theexperimental results show that the VSR process is effective.