Traditional　buckling　restrained　braces　are　widely　used　in　buildings,　but　the　structure　may　have　large　residual　deformation　after　earthquakes,　which　is　not　easy　to　repair.　This　paper　presents　a　new　self-centering　replaceable　mild　steel　energy-dissipating　brace　and　a　theoretical　design　method.　Low　cyclic　loading　tests　on　the　new　brace　specimens　with　the　scale　factor　of　0.6　were　conducted　to　study　the　mechanical　performance.　Besides,　numerical　simulation　is　carried　out,　and　the　results　are　compared　with　the　test.　The　results　show　that　the　new　self-centering　replaceable　mild　steel　energy-dissipating　braces　can　achieve　good　energy　dissipating　performance　through　high-order　buckling,　the　plastic　deformation　of　the　main　body　is　not　affected　during　the　loading　process.　Meanwhile,　the　residual　deformation　is　very　small　and　the　structure　has　a　good　self-centering　capacity　and　mechanical　performance.　The　appropriate　reduction　of　the　distance　between　the　steel　brackets,　the　multi-order　buckling　and　plastic　development　of　the　mild　steel　energy　dissipating　members　are　preferred,　because　the　energy　dissipation　capacity　of　the　braces　can　be　improved　especially　when　the　braces　are　under　compression.　With　the　replacement　of　the　mild　steel　energy-dissipating　segments,　the　braces　can　continue　to　work.　The　design　objective　of　self-centering　replaceable　mild　steel　members　can　be　achieved.　©　2017,　Engineering　Mechanics　Press.　All　right　reserved.