This　study　analyses　the　working　mechanism　and　seismic　performance　index　of　I-section　steel-reinforced　concrete　columns　with　concealed　double　steel　plates　and　bottom-strengthened　I-section　concrete-filled　steel　tube　columns　subjected　to　compression-bending　load.　For　this　purpose,　six　column　models　with　different　constructions　were　tested　under　horizontal　low　cyclic　loading.　Based　on　the　experiments,　the　load-bearing　capacity,　stiffness　and　degradation　process,　ductility,　hysteretic　energy　dissipation　capacity　and　failure　characteristics　of　the　models　were　analysed.　The　formulae　for　calculating　the　load-bearing　capacity　for　the　normal　and　oblique　sections　of　I-section　steel-concrete　composite　columns　were　derived,　and　the　finite　element　(FE)　numerical　simulation　of　the　classical　specimens　was　performed.　According　to　the　results,　the　load-bearing　capacity,　ductility　and　seismic　energy　dissipation　capacity　of　the　bottom-strengthened　I-section　steel-concrete　composite　columns　are　obviously　improved　when　compared　with　those　of　the　conventional　I-section　steel-concrete　composite　columns.　Moreover,　the　calculated　and　FE　numerical　simulation　results　are　found　to　be　in　good　agreement　with　the　experimental　results.　Further,　the　bottom-strengthened　I-section　steel-concrete　composite　column　shows　better　seismic　behaviour　and　higher　energy　dissipation　capacity　under　suitable　constructional　requirements,　indicating　their　suitability　for　constructing　high-rise　buildings.