Because　large　plastic　deformation　occurs　in　hydroforming　bellows　there　is　a　residual　stress　distributing　in　the　metal　after　forming,　which　is　complex　and　not　easy　to　be　measured.　The　existence　of　residual　stress　might　have　an　effect　on　the　corrosive　property　and　bulking　performance　of　bellows.　A　finite　element　model　was　established　to　simulate　the　forming　residual　stress　of　the　nickel　alloy　multi-layer　bellow.　The　distribution　of　residual　stress　was　calculated　out　and　validated　by　cos　alpha　X-ray　diffraction　measurement.　Thus　the　forming　mechanics　and　the　effects　of　layer　number　and　forming　pressure　on　the　residual　stress　in　the　hydroforming　bellow　were　both　discussed　in　detail　based　on　the　established　model.　It　was　shown　that　the　calculated　residual　stress　had　the　same　trend　with　the　experimental　results.　The　axial　and　circumferential　residual　stresses　at　the　outer　surface　of　the　peak　were　both　compressive.　There　existed　the　maximal　Von　Mises　stress　at　the　inner　surface　of　the　peak　of　the　bellow.　At　this　position　the　radial　and　axial　residual　stresses　were　both　tensile.　When　applying　multi-layer　bellows　and　less　forming　pressure　a　lower　forming　residual　stress　could　be　obtained　because　of　the　narrow　plastic　strain　region　during　forming.