Gas　production　by　depressurization　can　significantly　increase　the　effective　stress　in　hydrate-bearing　sediments.　Therefore,　strength　and　deformation　characteristics　of　sediments　under　high　effective　confining　pressure　should　be　fully　understood　before　large-scale　extraction.　In　this　study,　a　series　of　triaxial　tests　on　artificial　methane　hydrate-bearing　specimens　were　conducted　under　effective　confining　pressures　of　0.2-20　MPa,　and　the　effects　of　effective　confining　pressure　and　hydrate　saturation　on　the　strength　parameters　and　the　stress-dilatancy　characteristics　were　discussed.　The　results　demonstrate　that　the　strength　and　stiffness　of　hydrate-bearing　sediments　increase　with　increasing　effective　confining　pressure.　Shearing　under　high　effective　confining　pressure　leads　to　significant　breakage　of　host　particles,　which　is　independent　of　the　hydrate　saturation.　The　increase　in　the　effective　confining　pressure　decreases　the　internal　friction　angle　while　increasing　the　cohesion　of　hydrate-bearing　sediments.　By　linking　the　effective　confining　pressure　and　hydrate　saturation　with　strength　parameters　of　Mohr-Coulomb　criterion　and　Drucker-Prager　criterion,　the　strength　of　sediments　in　a　high　range　of　effective　stress　can　be　accurately　predicted.　With　increasing　effective　confining　pressure,　the　shear-dilation　transfers　to　shear-contraction,　the　critical　stress　ratio　gradually　decreases　to　attain　a　constant　value,　and　the　effects　of　hydrate　saturation　and　effective　stress　on　the　dilatancy　characteristics　gradually　become　less　notable.