Suspend-dome　structure,　which　is　a　kind　of　semi-flexible　structure,　is　applied　in　the　roof　steel　structure　of　the　badminton　gymnasium　for　2008　Olympic　Games.　The　overall　stability　of　the　structure　is　a　dominating　factor　during　the　design.　Suspend-dome　structure　is　featured　by　close　buckling　eigenvalues　and　local　buckling　modes.　This　paper　attempts　to　analyze　the　effect　of　calculation　method,　material　elastic-plasticity,　connection　detail　and　prestressing　loss　on　the　overall　stability　of　suspend-dome.　The　study　indicates　that　load　substep,　material　elastic-plasticity　and　the　cable-strut　joint　have　significant　effect　on　the　overall　stability　of　the　suspend-dome　of　the　badminton　gymnasium　for　2008　Olympic　Games.　Finally,　a　long-span　steel　structures　performance　design　based　on　structural　overall　stability　is　presented　and　the　overall　stability　coefficient　is　suggested.