In order to investigate the seismic effect and optimal design of fixing cultural relics by the most commonly used fasteners in the museum， the shaking table tests are carried out on the typical large fragile cultural relics replicas with different shapes （porcelain vase） fixed by fasteners under different working conditions. The key geometric parameters affecting the motion state of cultural relics replicas are obtained and the seismic effectiveness of the independent fasteners on larger cultural relics is discussed. Based on the test results， numerical methods are established for seismic systems of cultural relics with fixing measures， and the parametric analyses of key influencing factors are carried out to obtain the minimum sizes of fasteners required to effectively fix cultural relics with different sizes under earthquake actions. It provides the necessary basis for optimal design of fixing measures in consideration of safety and minimum intervention principle. The results show that the conformal fasteners could effectively fix larger-size cultural relics compared with cylindrical fasteners. For the cultural relics with uneven body and high center of gravity， the height， outline width and bottom diameter （area） significantly affecte their dynamic responses and the interaction behavior. The larger outline width/bottom diameter and height/bottom diameter， the more obvious swing responses will be observed. To ensure the safety of cultural relics， it is recommended that the gap between fasteners and cultural relics should not be larger than 2 mm. Adding rubber pads or silicone pads could reduce the interaction force between cultural relics and fasteners by 60%~ 70%， which effectively prevented the cultural relics from being damaged. In the case of the size of cultural relics exceeded a certain limit， the independent fastener method is no longer applicable， and it is suggested to adopt combining fixing measures （fasteners and fishing lines）. For the cultural relics in the case of larger swing responses fixed with cylindrical fasteners compared with floating state， it is better to adopt conformal fasteners or combining fixing measures.