The　depressurization　method　that　is　used　to　produce　methane　gas　can　increase　the　effective　stress　in　hydrate-bearing　sediments　and　induce　deformation　and　settlement　of　reservoirs,　which　has　adverse　effects　on　safe　and　stable　exploitation.　A　series　of　isotropic　consolidation　and　depressurization　dissociation　tests　under　high　effective　confining　pressures　on　methane　hydrate-bearing　specimens　were　conducted　to　investigate　compressive　characteristics　and　deformation　behaviors.　Isoconsolidation　test　results　demonstrated　that　the　rise　in　effective　confining　pressure-induced　increasing　compressibility　and　particle　crushing　of　sediment,　while　the　presence　of　hydrates　can　suppress　compressibility　and　crushing.　The　compression　index　tends　to　increase　with　increasing　effective　stress　but　decrease　with　increasing　hydrate　saturation.　Dissociation　test　results　suggested　that　higher　effective　stress　during　dissociation　and　higher　deviatoric　stress　led　to　more　significant　deformation　and　particle　breakage.　A　specimen　can　exhibit　serious　deformation　(e(v)　approximate　to　20%)　after　dissociation　when　the　effective　stress　is　extremely　high　(17　MPa),　even　if　the　stress　state　is　in　the　stable　zone.　During　water　recovery　after　dissociation,　axial　and　volumetric　strains　may　further　increase　under　the　combined　effect　of　deviatoric　stress　and　high　effective　confining　pressure.