Aiming　at　the　seismic　behavior　of　high-strength　concrete-filled　thin-walled　steel　tubular　(HCFTST)　columns　under　low　cycle　reciprocating　loading,　a　quasi-static　test　was　conducted　on　eight　Q690　HCFTST　columns　with　out-of-code　diameter-to-thickness　(D/t)　ratios.　The　failure　mode,　hysteretic　and　skeleton　curves,　ductility　coefficients,　energy　dissipation,　stiffness　and　load　degradation　were　analyzed　in　detail　to　reflect　the　influences　of　axial　compression　ratios,　D/t　ratios　and　concrete　strengths　on　the　key　performance　indicators.　Subsequently,　the　lateral　shear-resistant　capacity　was　examined　to　develop　a　simplified　calculation　formula　based　on　the　truss　mechanism.　The　result　indicates　that:　the　failure　modes　of　the　tested　Q690　HCFTST　columns　can　be　generally　divided　into　flexure-dominated　or　shear-dominated　failure,　and　the　former　performs　a　plumper　hysteretic　behavior　than　the　latter;　the　ductility　coefficients　are　in　the　range　of　1.99　-　2.89　while　the　degradation　ratios　of　bearing　capacity　maintain　above　0.9　in　the　drifts　of　1%　-　6%,　moreover,　the　tested　out-of-code　HCFTST　columns　exhibit　a　reasonable　hysteretic　performance　and　plastic　deformation　capacity;　the　axial　compression　ratio　ought　to　be　reasonably　improved　to　heighten　the　ductility,　lateral　stiffness　and　energy　dissipation;　the　prediction　results　of　the　proposed　shear-resistant　calculation　model　based　on　truss　mechanism　coincide　well　with　the　test　values,　implying　this　method　can　serve　as　a　practical　tool　in　evaluating　the　lateral　shear-resistant　capacity　for　the　HCFTST　columns　suffered　from　the　strength-controlled　failure.　©　2020,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.