To　investigate　the　dynamic　response　and　fire　performance　of　steel　beams　under　high　temperature,　drop　hammer　impact　tests　and　numerical　simulations　were　conducted　on　steel　beams　subjected　to　high　temperatures.　Three　finite　element　(FE)　models　were　established　using　the　element　coupling　method　to　predict　the　impact　dynamic　behavior　of　the　steel　beams　under　the　combined　effects　of　fire　and　impact　loads.　The　reliability　and　applicability　of　the　developed　FE　models　in　predicting　the　impact　dynamic　response　of　steel　beams　in　fire　was　examined　through　comparison　of　numerical　results　with　experimental　results.　Based　on　the　experimentally　and　numerically　observed　failure　modes,　a　generalized　plastic　yield　criterion　for　I-shaped　steel　beams　section　was　proposed,　which　considers　the　synergistic　effects　of　axial　force,　shear　force,　bending　moment,　strain　rate,　and　temperature　with　the　plastic　deformation　of　the　entire　cross　section　as　the　criterion.　The　interaction　functions　and　spatial　characteristics　between　internal　forces　were　presented.　A　new　generalized　yield　(G-Y)　method　for　evaluating　the　failure　of　components　due　to　plastic　hinges　development　without　restricting　the　load　type　was　proposed　based　on　four　types　of　interaction　relationships　combination,　and　the　sensitivity　of　the　G-Y　method　to　different　parameters　for　assessing　the　development　of　plastic　hinges　was　systematically　studied.　Based　on　the　proposed　G-Y　method,　the　mechanical　behavior　of　steel　beam　subjected　to　multiple　extreme　load　coupling　effects　was　revealed.