The　coupled　discrete　element　and　lattice　Boltzmann　method　using　an　immersed　moving　boundary　scheme　was　extended　to　simulate　methane　hydrate　exploitation　involving　mass　transport　and　particle　dissolution.　In　this　coupled　DEM-IMB-LBM　model,　a　new　Dirichlet-type　thermal　boundary　condition　is　extended　to　simulate　moving　curved　boundaries　with　constant　concentration.　A　novel　periodic　boundary　including　an　efficient　searching　algorithm　for　particle　contact　is　proposed　to　reduce　the　computational　cost　and　boundary　effect.　Then　this　model　is　validated　by　two　numerical　examples:　a　circular　particle　with　concentration　convection-diffusion　moving　in　a　horizontal　channel　and　mass　transport　from　a　cylinder　particle　in　a　simple　shear　flow.　The　numerical　results　obtained　from　the　proposed　model　agree　well　with　previous　studies.　To　further　demonstrate　the　capacity　of　the　proposed　model,　simulations　of　methane　hydrate　exploitation　including　two　formations　in　marine　sediments　are　carried　out.　The　numerical　results　indicate　that　the　coupled　DEM-IMB-LBM　is　not　only　capable　of　simulating　the　dissolution　of　hydrate　particles　at　the　grain　level,　but　also　recover　the　sand　erosion　and　migration　process　in　a　fundamental　perspective　during　the　methane　hydrate　exploitation　process.