Aiming　at　the　problem　of　cable　breakage　of　an　asymmetric　single-tower　cable-stayed　bridge　by　taking　a　single-tower　cable-stayed　bridge　that　has　been　in　operation　for　more　than　20　years　as　an　engineering　example,　a　spatial　finite　element　model　that　reflected　the　actual　stress　state　of　the　structure　was　established　and　a　method　for　solving　the　time　point　of　cable　breakage　was　proposed.　The　results　show　that　the　strength　of　the　main　girder,　pylon　and　cable　could　meet　the　stress　requirements　of　the　vibration　caused　by　successive　cable　breaks,　and　the　maximum　dynamic　displacement　of　the　main　girder　did　not　exceed　the　stiffness　limit.　Although　the　breakage　of　the　stay　cable　caused　the　stress　in　the　adjacent　position　and　the　corresponding　position　on　the　opposite　side　of　the　tower　to　increase　sharply,　the　stress　fluctuation　in　other　positions　was　small.　The　fluctuation　of　the　dynamic　stress　of　the　cable　tower　was　relatively　small,　but　the　displacement　of　the　tower　top　changed　greatly.　The　dynamic　response　of　the　cables　breaking　in　succession　was　less　than　that　of　simultaneous　breaking,　and　the　structural　vibration　caused　by　cable　breaking　was　not　as　severe　as　that　caused　by　simultaneous　breaking.