The　lumen　parts　of　sterilizer　pressure　vessels　are　generally　welded　by　austenitic　stainless　steel　and　there　will　be　serious　stress　corrosion　that　caused　by　the　common　action　by　the　welding　residual　stress　and　corrosion　medium.　Over　load　method　can　be　used　to　reduce　the　residual　stress.　The　finite　element　method　(FEM)　and　experiment　are　adopted　to　quantitively　analyze　the　effect　of　over　load　tension　on　residual　stress.　At　first,　SYSWELD　software　is　used　to　calculate　the　welding　residual　stress　contour,　and　then　Nastran　software　is　used　to　simulate　the　over　load　tensionprocess　to　investigate　the　variation　of　the　residual　stress.　The　simulation　results　show　that　with　the　increase　of　tensile　strain,　the　maximum　values　of　welding　residual　stress　were　reduced　dramatically,　and　the　welding　residual　stress　contours　become　more　uniform.　However,　once　the　value　of　tensile　strain　exceeds　a　certain　critical　value,　the　effect　of　reducing　welding　residual　stress　turn　to　being　gradually　weakened.　The　simulation　results　were　agreed　well　with　X　ray　measurement　results,　which　shows　that　this　method　is　feasible.　Such　research　methods　and　results　will　provide　reference　for　the　elimination　of　welding　residual　stress　and　welding　quality　control.　©　2016,　Editorial　Board　of　Transactions　of　the　China　Welding　Institution,　Magazine　Agency　Welding.　All　right　reserved.