The　overall　stability　of　high　and　large　formwork　support　systems　with　fastening　style　steel　pipe　was　analyzed　by　finite　element　software　ABAQUS.　The　semi-rigid　connection　relationship　of　fasteners　was　simulated　by　the　spring　element　and　the　initial　defects　were　applied　by　the　buckling　mode.　By　comparing　the　finite　element　calculation　results　and　the　measured　results　at　three　engineering　projects,　the　accuracy　of　the　finite　element　model　was　verified.　The　influence　of　some　parameters,　such　as　fastener　tighten　torque,　support　height,　cross　rod　drawing　space,　vertical　rod　longitudinal　space,　vertical　rod　transverse　space　and　the　initial　defect,　was　analyzed.　The　results　show　that　the　cross　rod　drawing　space,　vertical　rod　transverse　space　as　well　as　the　initial　defect　have　significant　effects　on　the　overall　stability　bearing　capacity　of　high　and　large　formwork　support　systems　with　fastening　style　steel　pipe.　The　bearing　capacity　decreases　quickly　with　the　increase　of　cross　rod　drawing　space,　vertical　rod　transverse　space　and　scale　factor　of　buckling　mode.　By　adjusting　the　calculated　length　coefficient　of　vertical　rod,　the　analysis　model　for　the　overall　stability　bearing　capacity　can　be　simplified　as　a　vertical　rod.　In　the　end,　a　simplified　formula　for　the　calculation　length　coefficient　is　put　forward,　which　can　provide　reference　for　the　engineering　application.　©　2016,　Editorial　Office　of　China　Civil　Engineering　Journal.　All　right　reserved.