Long-period　ground　motion　is　easy　to　cause　strong　seismic　response　of　isolated　structure，which　may　be　more　disadvantageous　when　considering　soil-structure　interaction　（SSI　effect）.　In　order　to　explore　the　influence　of　the　SSI　effect　of　the　weak　interlayer　foundation　under　the　long-term　period　of　ground　vibration　on　the　dynamic　response　law　and　shock　absorption　performance　of　the　layer　interval　vibration　structure，the　numerical　simulation　and　vibration　platform　test　of　the　single　tower　layer　interval　vibration　structure　of　the　large　chassis　on　the　rigid　and　soft　interlayer　foundation　are　carried　out.　The　results　show　that　the　soft　interlayer　foundation　has　an　obvious　amplification　and　filtering　effect　on　the　input　ground　vibration，which　is　associated　with　the　peak　and　spectral　characteristics　of　the　ground　vibration.　After　considering　SSI　effect，the　natural　vibration　period　of　the　structure　is　larger　than　that　of　the　rigid　foundation，but　the　extended　period　multiple　of　the　isolation　technology　is　lower.　The　SSI　effect　enlarges　the　acceleration　response　to　the　lower　chassis　and　the　diaphragm，and　may　increase　or　decrease　the　acceleration　response　of　the　upper　tower，depending　on　the　type　and　intensity　of　the　input　seismic　vibration.　After　considering　the　SSI　effect，the　seismic　response　of　the　isolation　structure　under　long-period　ground　motions　is　stronger　than　that　of　ordinary　ground　motions，and　the　damping　effect　becomes　worse.　In　particular，the　displacement　of　the　isolation　layer　under　near-field　impulse　ground　motions　exceeds　the　limit，the　damping　effect　is　poor，and　the　system　fails.　©　2023　Nanjing　University　of　Aeronautics　an　Astronautics.　All　rights　reserved.