Global　bifurcations　and　Shilnikov　type　multipulse　chaotic　dynamics　for　a　nonlinear　vibration　absorber　are　investigated　by　using　the　energy-phase　method　for　the　first　time.　A　two-degree-of-freedom　model　of　a　nonlinear　vibration　absorber　is　considered.　After　the　nonlinear　nonautonomous　equations　of　this　model　are　given,　the　method　of　multiple　scales　is　used　to　derive　four　first-order　nonlinear　ordinary　differential　equations　governing　the　modulation　of　the　amplitudes　and　phases　of　the　two　interacting　modes　in　the　presence　of　1:1　internal　resonance　and　primary　resonance.　Using　several　coordinate　transformations　to　transform　the　modulation　equation　into　a　standard　form,　we　can　apply　the　energy-phase　method　to　show　the　existence　of　the　multipulse　chaotic　dynamics　by　identifying　Shilnikov-type　multipulse　orbits　in　the　perturbed　phase　space.　We　are　able　to　obtain　the　explicit　restriction　on　the　damping,　forcing　excitation　and　the　detuning　parameters,　under　which　the　multipulse　chaotic　dynamics　is　expected.　These　multipulse　orbits　represent　the　repeated　departure　from　purely　vertical　oscillations　for　the　nonlinear　vibration　absorber.　Numerical　simulations　also　indicate　that　there　exist　different　forms　of　the　multipulse　chaotic　responses　and　jumping　phenomena　for　the　nonlinear　vibration　absorber.