The　application　of　the　particle　damping　technology　in　civil　engineering　is　limited　owing　to　the　complex　nonlinear　mechanical　properties　and　lack　of　a　reasonable　mechanical　model.　The　existing　equivalent　single-particle　model　cannot　include　the　interactions　between　particles.　In　addition,　an　appropriate　determination　of　parameters　is　required.　In　this　study,　to　consider　the　influence　of　the　interactions　between　particles,　a　dual-mass　equivalent　model　(DMEM)　is　proposed　based　on　a　particle　motion　state　analysis.　A　shaking　table　test　on　a　single-story　frame　under　a　harmonic　excitation　was　carried　out　to　verify　the　rationality　of　the　model.　The　variations　in　connection　stiffness　k　and　damping　coefficient　c　with　the　filling　ratio　were　evaluated.　Experiments　under　earthquake　excitations　were　carried　out　to　verify　the　adaptability　of　the　model.　The　comparison　between　the　DMEM　and　the　existing　equivalent　model　was　also　conducted　to　verify　the　simulation　accuracy　of　the　model.　Then,　the　effect　and　mechanism　of　the　multiparticle　damper　were　analyzed　based　on　the　DMEM　with　the　optimal　stiffness　k.　The　mass　coupling　coefficient　had　significant　effects　on　the　damping　and　mechanism　of　the　multiparticle　damper.　Although　it　is　different　from　the　actual　multiparticle　damper,　the　proposed　DMEM　is　of　significance　for　the　further　development　and　applications　of　multiparticle　dampers　in　civil　engineering.