This　study　utilizes　the　superelasticity　property　of　shape　memory　alloy　(SMA)　to　form　a　shape　memory　alloy　spring-　based　tuned　vibration　absorber　(SMA-TVA)　for　mitigating　vibrations　in　multi-degree-of-freedom　(MDOF)　structures.　Nitinol　SMA　is　chosen　for　the　fabrication　of　SMA　specimens,　and　cyclic　displacement　loading　tests　are　performed　on　both　SMA　wire　and　spring.　Shaking　table　tests　are　then　designed　and　executed　on　a　three-story　steel　shear　frame　under　tuned　vibration　absorber　(TVA)　and　SMA-TVA　control,　respectively.　Four　seismic　waves　are　selected　to　compare　the　performance　of　two　dampers,　with　a　specific　focus　on　the　time-frequency　energy　evolution　of　the　MDOF　structure　under　different　excitations.　Furthermore,　the　robustness　of　SMA-TVA　is　validated　across　varying　excitation　amplitudes　and　frequency　ratios.　Results　reveal　that　SMA-TVA　effectively　attenuates　vibrations　beyond　its　tuning　frequency,　dissipating　energy　associated　with　multiple　modes.　It　outperforms　TVA　with　a　significant　109.3%　and　85.2%　improvement　in　RMS　displacement　and　acceleration　reduction,　respectively,　with　strokes　reduced　by　up　to　42.5%　under　earthquakes.　Certain　earthquakes　exhibit　a　prolonged　period　of　high　energy　input,　facilitating　more　efficient　and　stable　attenuation　of　vibrations　for　SMA-TVA.　The　average　change　in　the　vibration　reduction　ratio　remains　below　13.7%　within　the　considered　varying　frequency　ratios,　indicating　that　SMA-TVA　exhibits　robustness　against　tuning　frequency　deviation.