In　this　paper,　the　experimental　investigation　was　carried　out　on　the　TC4　titanium　alloy　to　understand　the　cyclic　deformation　behavior　and　fatigue　damage　mechanism　of　materials　under　multiaxial　thermo-mechanical　loading.　The　results　showed　that　the　fast　cracking　mode　of　the　material　may　be　activated　by　the　combined　action　of　high　temperature,　tensile　stress　and　shear　stress,　inducing　a　fast　degradation　in　the　axial　mechanical　properties　of　the　material,　which　results　in　a　drastic　decrease　in　the　failure　life　of　the　material.　Moreover,　it　is　also　found　that　the　non-proportional　additional　hardening　and　the　tensile　mean　stress　can　increase　the　fatigue　and　oxidation　damages　of　the　material,　and　the　material　damage　behavior　is　temperature　dependent　and　time　dependent.　It　should　be　pointed　out　that　the　damage　mechanisms　identified　in　this　paper　can　reasonably　explain　the　life　law　under　uniaxial　isothermal　fatigue　loading　with　and　without　dwell　time,　uniaxial　and　multiaxial　thermomechanical　fatigue　loadings.