Compared with the conventional seismic isolation bearing, shape memory alloys（SMA） isolation bearing improves the self-centering and energy dissipation ability of the structure. However, premature intervention of SMA may increase the internal force and acceleration response of the superstructure during moderate and small earthquakes. In order to solve this problem, introducing gap into SMA isolation bearings, such composite device meets different performance requirements. Firstly, the configuration of gap-SMA bearing was proposed, and physical tests on SMA wires were conducted; afterwards, a two-degree-of-freedom model of a base-isolated building was used as a test bed, where the effects of gap length and SMA yield force on shock absorption were discussed; last, aim at reducing the internal force and acceleration response of the gap-SMA isolation bearing under large earthquakes or giant earthquakes, negative stiffness mechanism is further introduced to gap-SMA isolation system, followed by the feasibility analysis of combination negative stiffness with gap-SMA friction pendulum system. The results show that gap-SMA isolation bearing can effectively reduce the internal force and acceleration response of the superstructure under medium and small earthquakes; the acceleration response of the superstructure is negatively correlated with gap length and positively correlated with SMA yield force; the displacement response of the substructure is positively correlated with gap length and negatively correlated with SMA yield force. Incorporating with negative stiffness, gap-SMA bearing can control the displacement of the substructure and reduce the internal force of the structure simultaneously.