In　the　current　study,　a　multiaxial　multiscale　compressive　stress-strain　model　for　Fiber　Reinforced　Cementitious　Composites　(FRCC)　was　innovatively　developed.　The　proposed　model　was　on　the　basis　of　the　theory　of　thermodynamics,　multiscale　theory　and　internal　variable　theory.　The　free　energy　function　and　dissipation　function　were　established　to　characterize　the　elastic　and　plastic　deformation　of　FRCC,　respectively.　The　multiscale　behaviors　of　FRCC　in　meso-scale　and　macro-scale　was　taken　into　account.　In　meso-scale,　the　energy　dissipation　functions　of　fiber　in　tension　and　bond-slip　deformation　in　the　interface　transition　zone　(ITZ)　were　established.　The　resistance　to　cracking　of　cementitious　matrix　through　the　fiber　bond　stress　were　taken　into　account.　In　macro-scale,　the　thermo-mechanical　coupling　contributions　of　plastic　damage,　thermal　damage,　yield　surface　and　hardening　evolution　were　creatively　considered　in　the　potential　function　within　thermodynamics　framework.　The　influence　of　types　and　volume　fractions　of　fibers　on　the　reinforcement　mechanism　was　discussed.　When　the　temperature　is　higher　than　the　melting　point　of　fiber,　the　fiber　influence　coefficients　was　employed.　The　sensitivity　of　yield　surface　was　discussed.　The　numerical　predictions　of　this　developed　model　were　carried　out　for　validation.　The　nonlinear　stress-strain　responses　of　concrete　were　accurately　captured　at　temperatures　ranges　from　20　°C　to　800　°C　compared　with　the　experimental　data,　which　indicates　the　accuracy　and　applicability　of　the　proposed　model.　©　2024　Elsevier　Ltd