Cable　dome　is　a　kind　of　lightweight　and　efficient　large-span　tensegrity　structure.　The　manufacturing　error　of　cable　length　will　seriously　affect　the　pre-stress　distribution　of　cable　dome　and　deviate　structural　performance　from　the　design　goal.　With　a　new　type　of　double-strut　cable　dome　as　calculation　example,　the　sensitivity　of　cable　length　error　to　structural　behavior　is　analyzed,　under　the　construction　method　of　＂fixed　length　cable＂.　Then,　using　reliability　theory　and　nonlinear　programming　method,　the　control　criteria　of　cable　length　error　are　obtained　for　this　structure.　The　accuracy　of　control　criteria　is　verified　by　the　Monte　Carlo　method.　The　results　show　that　for　the　double-strut　cable　dome,　the　length　errors　of　ridge　cables,　inner　diagonal　cables,　and　outer　hoop　cables　have　an　obvious　effect　on　the　internal　forces　of　other　cables.　The　method　used　in　this　paper　can　get　reliable　control　criteria　of　cable　length　error.　However,　the　excessive　allowable　error　in　specification　will　lead　the　structure　unable　to　meet　the　design　requirements.