The Gleeble-3800 thermal simulator was used to conduct isothermal constant strain rate thermal compression tests on TB15 titanium alloy to study its thermal deformation behavior at deformation temperatures of 810-930°C, strain rates of 0.001-10s-1 and height depression of 60%; three constitutive relationship models, physical, support vector regression (SVR) and response surface, were developed to predict the flow stresses of TB15 titanium alloy were predicted by three physical, support vector regression (SVR) and response surface constitutive models, and the prediction accuracy of the three constitutive models was compared. The results show that the flow stress of TB15 titanium alloy decreases with decreasing strain rate and increasing deformation temperature, and the change of peak stress is more sensitive to the strain rate; the correlation coefficient R of physical, SVR and response surface constitutive models are all greater than 0.98, but the R value of response surface constitutive model reaches 0.993, and the frequency of the relative error of the response surface constitutive models ±5% of the predicted value reached 67.9%, which was greater than that of the physical constitutive models at58.6%. The significance test value P<0.0001 of the constructed response surface constitutive model was also obtained by ANOVA, indicating that the regression relationship between the flow stress predicted by the response surface constitutive model and the deformation temperature, strain rate and strain was significant and had higher accuracy than the physical constitutive model and SVR constitutive model, which could better predict the flow stress of TB15 titanium alloy.