Due　to　the　excellent　bearing　capacity,　high-strength　steel　(yield　stress　≥　460　MPa)　is　gradually　utilized　in　the　design　of　super　high-rise　buildings,　long-span　bridges　and　other　important　structures　to　reduce　section　size　and　self-weight.　In　the　present　study,　the　axial　compression　test　and　numerical　simulation　were　carried　out　to　investigate　the　global　buckling　of　high　strength　steel　tubes.　Eighteen　specimens　of　Q690　high　strength　circular　steel　welded　tubes　were　tested　under　axial　compression　to　obtain　the　ultimate　bearing　capacity　and　buckling　mode.　An　effective　finite　element　numerical　model　incorporating　the　residual　stress　and　geometric　imperfection　was　established　to　analyse　the　influence　of　slenderness　ratio,　diameter　thickness　ratio　and　residual　stress　on　the　global　stability　coefficient.　According　to　the　calculation　results,　the　column　curve　of　Q690　circular　steel　tube　was　obtained　and　compared　with　three　different　codes.　Finally,　a　formula　to　calculate　the　global　stability　coefficient　of　Q690　welded　circular　steel　tubes　was　suggested.　©　2020　Institute　of　Physics　Publishing.　All　rights　reserved.