Compared　with　traditional　isolation　bearings,shape　memory　alloy　(　SMA)　isolation　bearings　can　improve　the　self-resetting　and　energy　dissipation　capacity　of　structures.　However,　early　intervention　of　SMA　may　increase　internal　forces　and　acceleration　responses　of　superstructure　during　moderate　and　small　earthquakes.　Here,　to　solve　this　problem,　gap-SMA　isolation　bearing　was　formed　by　introducing　gap　into　SMA　isolation　bearing　to　meet　isolation　requirements　of　different　fortification　targets.　Firstly,　the　physical　structural　form　of　gap-SMA　bearing　was　proposed,　and　cyclic　tensile　tests　of　SMA　wire　were　conducted.　Then,　a　simplified　model　of　2D0F　frame　structure　was　taken　as　an　example　to　explore　effects　of　gap　length　and　SMA　yield　force　on　isolation　effect.　Finally,internal　force　and　acceleration　response　of　gap-SMA　isolation　bearing　was　reduced　under　large　or　great　earthquake,　the　negative　stiffness　mechanism　was　further　introduced　to　improve　gap-SMA　isolation　system,　and　explore　the　feasibility　of　negative　stiffness-gap　type　SMA　bearing　isolation.　The　calculation　results　showed　that　gap-SMA　isolation　bearing　can　effectively　reduce　internal　forces　and　acceleration　responses　of　superstructure　during　moderate　and　small　earthquakes　;　acceleration　responses　of　superstructure　are　negatively　related　to　gap　length,and　positively　related　to　SMA　yield　force　;　displacement　responses　of　substructure　are　positively　related　to　gap　length　and　negatively　related　to　SMA　yield　force　;　after　introducing　negative　stiffness,gap-SMA　bearing　can　effectively　control　bearing　displacement　response　under　large　or　great　earthquake,and　significantly　reduce　internal　forces　and　acceleration　responses　of　superstructure.　©　2023　Chinese　Vibration　Engineering　Society.　All　rights　reserved.