To　solve　the　problem　of　multi-support　excitation　of　DEM,　large　mass　method　(LMM)　is　introduced　into　the　discrete　element　method　(DEM).　Based　on　proposed　member　discrete　element　method　(MDEM),　the　theoretical　formula　of　LMM　is　derived　and　the　corresponding　computing　program　is　compiled.　The　theory　indicates　that　the　error　of　LMM　depends　on　mass　proportional　damping　coefficient,　and　the　error　increases　as　it　becomes　larger.　Thus,　the　article　presents　herein　the　improved　large　mass　method　(ILMM)　according　to　the　correction　formula　acquired　from　earthquake　wave＇s　acceleration　time-history　curve.　Numerical　model　of　40　m-span　K8　single-layer　reticulated　spherical　shell　is　established　and　seismic　response　analysis　is　performed.　The　value　range　of　the　damping　and　large　mass　in　the　DEM　is　determined　first.　Then　the　dynamic　time-history　analysis　is　carried　out　using　relative　motion　method　(RMM),　LMM　and　ILMM　respectively.　The　comparative　results　show　that　ILMM　agrees　well　with　the　RMM　and　the　error　is　reduced　significantly.　Furthermore,　the　practical　applicability　and　accuracy　of　ILMM　in　the　MDEM　are　verified.　©　2016,　Editorial　Office　of　China　Civil　Engineering　Journal.　All　right　reserved.