A　unified　viscoplastic　constitutive　model,　which　can　consider　the　influences　of　non-proportional　hardening　and　dynamic　strain　aging　on　the　responded　stress,　was　proposed　under　axial-torsional　thermo-mechanical　cyclic　loading.　In　the　proposed　model,　the　rotation　factor　and　the　non-proportional　hardening　coefficient　were　considered　in　the　kinematic　hardening　rule.　And　the　dynamic　strain　aging　influence　factor　was　also　proposed　to　further　modify　the　kinematic　hardening　rule,　which　can　consider　the　induced　dynamic　strain　aging　under　special　strain　rate　and　temperature　conditions.　Moreover,　the　simulation　using　the　proposed　model　can　achieve　a　better　fit　with　the　measured　data　under　isothermal　and　non-isothermal　axial-torsional　cyclic　loadings.