In order to improve the application of the damping force of isolation device for free-standing objects， a new damping mechanism is developed. Its structure and working mechanism are expounded， and its mechanical characteristic is deduced and veri? fied. Combined with the target performance of an isolation device for cultural relics， the parameters of the damping mechanism are designed by numerical method， and contrasted with the shaking table test. The results indicate that the damping mechanism has a simple structure and stable performance. The isolation device optimized by damping parameters achieves the set isolation target un? der the premise of meeting the displacement limit. The test results are highly consistent with the numerical analysis results， which not only prove the correctness of the damping design， but also verifies the installation quality and operation effect of the isolation de? vice. In addition， the coincidence degree between two results can provide a new method for design comparison and quality evalua? tion of the isolation device， especially the coincidence degree of relative displacement curves.