Supercritical　water　(SCW)　fluidized　bed　reactors　release　no　pollutants　in　the　gasification　process　of　converting　biomass　into　fuel.　In　this　work,　a　mesoscale-structure-dependent　(MSD)　energy　minimization　multiscale　system　(EMMS)　drag　model　for　SCW　fluidized　beds　is　proposed.　Experimental　results　and　empirical　correlations　are　applied　to　validate　the　voidage　distribution　and　bubble　hydrodynamics　calculated　by　the　MSD-EMMS　model.　Besides,　this　study　presents　a　comparison　of　the　properties　of　computed　bubbles　between　the　Gidaspow　model,　EMMS/bubbling　model,　and　MSD-EMMS　model.　Bubble　properties　predicted　by　the　MSD-EMMS　model　agree　better　with　experimental　results　and　empirical　correlations　than　other　drag　models.　The　research　work　can　serve　as　guidance　for　the　optimization　of　SCW　gasification　technology.　©　2021　American　Chemical　Society.