The　intrinsic　relationship　between　hot　deformation　behavior　and　microstructure　evolution　in　Er,　Zr-microalloyed　Al-Cu-Mg　alloy　was　investigated　by　isothermal　hot　compression　test.　The　constitutive　model　and　thermal　process　map　were　established,　the　effects　of　the　Zener-Hollomon　parameter　(Z)　on　dynamic　recrystallization　and　precipitation　behavior　was　determined.　The　results　showed　that　the　predicted　value　of　the　strain-compensated　Arrhenius　constitutive　model　fit　well　with　the　friction　corrected　data　after　the　strain　fitting.　As　the　lnZ　value　increased,　the　deformed　alloy　exhibited　higher　dislocation　density,　smaller　average　grain　size　and　was　more　conducive　to　the　existence　of　large-sized　precipitates　(mainly　Al-Cu　phase,　Al-Mg-Si　phase,　Mn-Si-rich　phase).　The　L1(2)　ordered　Al-3(Er,　Zr)　particles　(similar　to　20　nm)　formed　by　the　co-addition　of　Er　and　Zr.　During　hot　deformation,　Al-3(Er,　Zr)　particles　and　Mn-Si-rich　phase　demonstrated　exceptional　thermal　stability　and　coarsening　resistance,　which　effectively　refined　the　grain　size　of　the　alloy　and　broadened　its　optimal　hot-working　window　(0.1-0.01s　(-1),　450-500　degrees　C).