Assembly portal supports and hangers have been widely used in engineering， but there is no corresponding seismic performance test method， and the research on seismic performance is also basically blank. In order to study the failure mechanism and seismic performance of supports and hangers under earthquake， a test method for seismic performance of different types supports and hangers is proposed， and low cyclic loading tests of sixteen specimens are carried out to investigate the effect of specimen size and seismic bracing on their seismic behavior. Results show that this method can systematically evaluate seismic performance of supports and hangers. Connecting nodes of specimens are weak due to large stress and slip， and usually fail before the main structure destroyed. Size of the specimens affects seismic performance. The higher the height， the smaller the elastic stiffness， bearing capacity and ductility coefficient， and the greater the stiffness degradation coefficient. Seismic bracing can improve seismic performance of the specimens. The elastic stiffness， bearing capacity and stiffness degradation of the specimens with seismic bracing are better than those of the specimens without seismic bracing. The ultimate bearing capacity is larger and the horizontal displacement is smaller than those of the specimens without seismic bracing when specimens destroyed. The research can provide a reference for the engineering application， quality inspection and standard formulation of supports and hangers.