The　distribution　of　the　residual　thermal　stress　(RTS)　in　the　as-sintered　cermets　and　its　interactions　with　the　applied　stress　were　studied　by　simulations　and　experiments,　using　the　WC-Co　cemented　carbides　as　examples.　The　influences　of　grain　size,　grain　morphology　and　phase　configuration　on　the　stress　state　and　mechanical　behavior　were　quantified　in　the　model,　which　was　constructed　from　real　multi-phased　microstructures.　The　results　indicate　that　the　volume-averaged　RTS　is　a　power　function　of　the　mean　WC　grain　size.　There　is　a　high　level　of　compressive　stress　in　the　WC　regions　near　the　triple　junctions　of　adjacent　WC　grains　and　Co　binder,　and　a　high　level　of　tensile　stress　inside　the　Co　phase　in　the　vicinity　of　WC/Co　phase　boundaries.　In　the　cermets　with　RTS,　the　metallic　binder　exhibits　a　gradually　increasing　strain　response　rate　under　the　external　loading.　It　is　found　that　a　smaller　WC　grain　size,　a　lower　proportion　of　Co　thin-layers,　and　a　higher　fraction　of　triple　junctions　of　adjacent　WC　grains　and　Co　phase,　are　beneficial　to　have　less　stress　concentration　and　simultaneously　high　strength　and　fracture　toughness　of　the　cermets.　This　study　provides　a　new　approach　to　characterize　stresses　in　the　multi-phased　materials　and　a　strategy　to　adjust　stress　distribution　by　tailoring　the　microstructure　for　excellent　comprehensive　mechanical　properties.　(c)　2021　Acta　Materialia　Inc.　Published　by　Elsevier　Ltd.　All　rights　reserved.