This　study　proposes　a　new　shape　memory　alloy-tuned　mass　damper　(SMA-TMD)　and　investigates　the　effectiveness　of　this　damper　in　reducing　and　controlling　the　vibrations　of　a　transmission　tower-line　system　under　various　seismic　excitations.　Based　on　a　practical　transmission　line　system　and　considering　the　geometric　nonlinearity　of　this　system,　the　finite　element　(FE)　software　ANSYS　is　used　to　create　an　FE　model　of　the　transmission　tower-line　system　and　simulate　the　proposed　SMA-TMD.　Additionally,　the　parameters　of　the　SMA　springs　are　optimized.　The　effectiveness　of　a　conventional　TMD　and　the　proposed　SMA-TMD　in　reducing　and　controlling　the　vibrations　of　the　transmission　tower-line　system　under　seismic　excitations　is　investigated.　Moreover,　the　effects　of　the　ground　motion　intensity　and　frequency　ratio　on　the　reduction　ratio　(eta)　of　the　SMA-TMD　are　studied.　The　vibration　reduction　effect　of　the　SMA-TMD　under　various　seismic　excitations　is　superior　to　that　of　the　conventional　TMD.　Changes　in　the　ground　motion　intensity　and　frequency　ratio　have　a　significant　impact　on　the.　of　the　SMA-TMD.　As　the　ground　motion　intensity　and　frequency　ratio　increase,　the.　values　of　the　SMA-TMD　first　increase　and　then　decrease.　Studying　the　vibration　reduction　effects　of　the　SMA-TMD　can　provide　a　reference　for　the　practical　engineering　application　of　this　damper.