Abstract: The isothermal compression tests of hydrogenated Ti6Al4V alloy at deformation temperature of 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃ and 1000 ℃ and strain rate of 1 s-1 were carried out on a Gleeble-1500 thermal simulator. The results show that the flow stress of Ti6Al4V alloy decreases first and then increases with the increase of hydrogen content. When the deformation temperature is 750℃, 800℃ and 850℃, the flow stress of alloy at hydrogenation content of 0.31wt% is the lowest. When the deformation temperature is 900℃, 950℃ and 1000℃, the hydrogen content corresponding to the minimum flow stress is 0.17wt%, 0.1wt% and as received, respectively. The high temperature deformation constitutive model of hydrogenated Ti6Al4V alloy was established based on the self-consistent model. The model reflected the effect of hydrogen on the flow stress of Ti6Al4V alloy by adjusting the strengthening effect of hydrogen on β phase and reducing the transition temperature of β phase. Compared with the experimental results, it is shown that the model can predict the variation of flow stress with hydrogenation content and deformation temperature well.