The　current　research　on　seismic　damage　of　existing　reinforced　concrete　structures　is　lack　of　considering　the　influence　of　two　typical　factors　together,　which　include　the　difference　of　different　seismic　design　codes　and　durability　degradation　on　the　structural　performance.　Furthermore,　the　index　represents　structural　damage　is　relatively　single,　which　has　limitations　in　dynamic　damage　analysis.　Based　on　the　characteristics　of　cloud　model,　and　considering　the　structural　responses　of　differential　ratio　of　elastic　plastic　dissipated　energy,　the　stiffness　damage　index,　the　interlayer　drift　ratio　and　the　top　drift　ratio　comprehensively,　a　multi-element　comprehensive　damage　evaluation　method　is　proposed,　which　can　contain　the　randomness　and　fuzziness　of　each　damage　index　together.　Considering　the　structural　inherent　seismic　performance　difference　caused　by　different　seismic　design　codes　and　the　influence　of　durability　degradation　on　structural　performance,　three　typical　five　story　reinforced　concrete　frame　structures　are　designed,　and　incremental　dynamic　analysis　is　carried　out　to　verify　the　accuracy　of　damage　assessment　method.　The　results　show　that　the　structural　damage　degree　decreases　gradually　with　the　update　of　the　version　of　the　seismic　code.　The　damage　degree　of　the　same　structure　reduced　firstly　and　then　increased　due　to　concrete　carbonation　develop,　and　the　differential　ratio　of　elastic　plastic　dissipated　energy　is　better　than　the　stiffness　damage　index　to　characterize　the　damage　of　existing　structures.　The　comprehensive　membership　degree　and　comprehensive　damage　value　of　cloud　model　of　structures　calculated　by　the　damage　assessment　method　of　multi　index　cloud　model　can　describe　the　damage　state　more　precisely.　©　2023　Science　and　Technology　Periodical　Press.　All　rights　reserved.