The　present　study　investigates　the　seismic　fragility　of　a　six-tower　cable-stayed　bridge　and　delves　into　the　influence　of　different　structural　system　types　on　this　bridge.　SeismoStruct　software　is　applied　to　establish　the　numerical　model　of　a　six-tower　cable-stayed　bridge,　and　its　accuracy　is　verified　through　a　shaking　table　test.　Then,　the　seismic　fragility　curves　of　this　bridge　are　generated　through　incremental　dynamic　analysis　to　assess　its　seismic　performance　under　longitudinal　earthquakes.　Then,　the　impact　of　the　different　structural　system　types　(the　number　of　towers　and　the　girder-pier　connection　form　in　the　longitudinal　direction)　on　the　seismic　fragility　of　the　cable-stayed　bridge　is　analysed.　The　results　show　that　the　fixed　bearing　is　the　most　vulnerable　component,　and　the　middle　pier　is　greatly　threatened　by　earthquakes.　With　the　decrease　in　the　number　of　towers,　there　is　a　slight　impact　on　the　seismic　fragility　of　the　fixed　bearing,　and　the　middle　pier　is　no　longer　the　most　vulnerable　bridge　pier.　Moreover,　the　damage　sequence　of　different　components　in　the　six-tower　cable-stayed　bridge　is　changed　in　the　longitudinal　consolidated　structural　system.　The　damage　probability　of　the　transition　and　the　side　piers　is　greater　than　that　of　the　middle　pier.