The　influence　of　steel　brace　buckling　on　inelastic　torsion　of　steel　braced　concrete　frame　structure　is　studied.　On　the　background　of　a　project,　the　shaking　table　test　results　of　two　structural　models　with　ordinary　steel　brace　(BRC)　and　buckling-restrained　brace　(BRB)　are　compared,　and　the　inelastic　torsion　and　sudden　increase　caused　by　steel　brace　buckling　is　confirmed.　Finite　element　analysis　models　with　BRC,　BRB　and　floor　load　eccentricity　are　established,　in　which　the　restoring　force　model　of　steel　brace　considered　the　asymmetry　of　tensile　and　compressive　bearing　capacity,　and　the　concrete　beam　and　column　members　considered　M3　and　PMM　hinge　respectively　to　study　the　process　and　characteristics　of　the　influence　of　BRC　buckling　on　the　nonlinear　torsion　of　the　structure.　The　mechanism　of　inelastic　torsion　of　steel　braced　concrete　frame　structure　(F-BRC)　induced　by　BRC　buckling　is　studied,　and　the　principle　that　the　dynamic　BRC　buckling　makes　the　structure　acquire　inertial　force　as　well　as　inertial　torsion　moment　is　found　out.　It　is　more　reasonable　to　explain　the　inelastic　torsional　process　and　the　mechanical　characteristics　of　the　structure　by　this　principle　than　by　the　theory　of　strength　eccentricity　and　stiffness　eccentricity.　Finally,　based　on　the　principle,　six　numerical　examples　with　different　brace　schemes　under　the　excitation　of　eight　earthquake　waves　are　calculated,　and　the　changing　rules　of　the　torsional　moment　are　studied.　Some　design　limitation　suggestions　are　put　forward.