The　shaking　table　test　of　three-story　subway　station　is　performed　to　study　the　failure　mechanism　of　multistory　underground　structure　in　earthquake.　Particle　concrete　is　chosen　to　make　the　testing　model,　and　the　reinforced　bar　is　set　strictly　according　to　the　similarity　ratio.　A　large-scale　shear　box　is　developed　to　reduce　the　boundary　effect.　By　analysis　of　acceleration　and　strain,　the　following　conclusions　are　drawn:　(1)　The　failure　of　underground　structure　in　earthquake　is　mainly　controlled　by　displacement.　(2)　As　to　multi-story　underground　structure,　the　uppermost　story　suffers　the　most　severe　damage　in　earthquake.　On　the　contrary,　the　lowest　story　suffers　the　slightest　damage.　(3)　Increasing　ductility　is　an　effective　method　to　improve　the　seismic　performance　of　underground　structures.