The thermal simulation compression experiment is used to study the thermal deformation behavior of EB furnace smelting TC4 titanium alloy at a strain rate of 0.01 s_^-1-10 s_^-1 and a deformation temperature of 800 ℃-1100 ℃, and calculate the strain rate of the alloy under different deformation conditions Sensitivity index m, and based on the DMNR model to establish a dual multivariate nonlinear regression constitutive equation for EB furnace smelting TC4 titanium alloy. The results show that at the beginning of deformation, work hardening is dominant, and the flow stress increases with the increase of strain. When the peak stress is reached, the softening effect is more obvious, the dislocations begin to slip and climb, and the flow stress increases with the strain. Increase and decrease. The value of m is larger under low temperature and small strain rate, and smaller under high temperature and large strain rate. The larger the value of m, the more uniform the corresponding microstructure. The established nonlinear regression constitutive equation can better predict the flow stress of EB furnace smelting TC4 titanium alloy. The average absolute relative error between the predicted value and the measured value is 5.83%, and the correlation coefficient is 0.98.