The　safety　and　comfort　under　the　crowd　jumping　and　landing　are　necessary　to　be　considered,　especially　for　studying　the　vibrations　of　flexible　floor　with　long　span.　An　equivalent　four　rigid　body　model　for　human　body　was　established　by　setting　the　joint　angles　of　each　rigid　axis　as　the　generalized　coordinates,　and　the　human　dynamic　characteristics　in　the　process　of　jumping　and　landing　were　analyzed.　The　time-varying　forces　that　human　exert　to　the　floor　could　be　calculated　according　to　the　changes　of　different　joint　angles.　The　dynamic　loads　of　the　human　were　simulated　according　to　multiple　rigid　body　method　and　combinational　sinusoidal　loading　method　and　the　dynamic　equation　for　damped　floor　and　its　solution　were　studied.　The　dynamic　performance　under　crowd　excitation　for　floors　with　different　structural　parameters　was　studied,　and　the　comfort　was　also　evaluated.　Results　show　that　the　combinational　sinusoidal　loading　method　which　simulates　crowd　excitation　is　more　suitable　for　routine　floor　design　and　the　multiple　rigid　body　method　simulated　the　crowd　excitation,　owing　to　its　abundant　frequencies,　can　be　considered　when　the　comfort　for　large　span　floor　is　evaluated.