Base　on　a　long-span　cable-stayed　bridge　with　twin　towers.　According　to　the　design　data　and　the　load　test,　FEM　is　established　and　modified　to　meet　the　actual　structure.　By　using　the　theory　of　FEA　and　calculation　of　the　design　load　and　structural　mechanics　performance,　＇Theoretical　spectra＇　of　static　characteristics　of　structures　are　established.　On　the　basis　of　load　test,　the　most　unfavorable　section　and　vulnerable　parts　of　the　bridge　are　obtained.　Then　＇Standard　spectrum＇　of　bridge　structure　under　the　action　of　standard　design　load　is　established.　Combining　theoretical　analysis　with　the　sensor　layout　method　commonly　used　in　long-span　cable-stayed　bridges,　the　sensor　layout　scheme　is　finally　obtained　according　to　the　＇theoretical　spectrum＇,　the　＇standard　spectrum＇　and　the　sensor　optimization　arrangement　theory.　The　sensor　placement　method　presented　in　this　paper　is　feasible　and　effective,　and　provides　a　scientific　theoretical　basis　for　the　sensor　placement　scheme.　It　can　be　used　as　a　real-time　monitoring　sensor　placement　method　for　similar　bridges.　©　Published　under　licence　by　IOP　Publishing　Ltd.