Abstract: Fixture is the exciting force of vibration table is passed to a equipment of power transmission components, in the past most of the fixture design and modal analysis in the paper, the connection of fixture and foundation simplified as rigid connection, through the finite element analysis gives the fixture of the previous order modal, but in actual use, clamp the measured resonance frequency and the main mode of the theoretical value have larger deviation. In this paper, a sea of vibration test fixture for the electronic device, for example,proved that the fixture calculating modal and the measuredmodal exists bigger difference, according to the actual use of the fixture, the corresponding mechanical model was established, through the analysis shows that the actual when using fixture with bolt connection is rigid connection characteristics of vibration table, in the huge sea equipment fixture design, fixture simple analysis method of joint stiffness and vibration table for your reference.