High-temperature flow behaviors of a spark-plasma-sintered Ti-6Al-4V alloy was studied at a temperature range of 850-1050°C and a strain rate of 0.001-5 s-1 on a Gleeble-1500D simulator. The true stress-strain curve of the alloy deformed at the total strain of about 70 % was studied. The results show that the flow stress increased as the deformation temperature decreased and the strain rate increased. Based on an Arrhenius-type equation, a constitutive equation was established. In the constitutive equation, the strain has a significant influence on the material parameters, and the relationships between the material parameters and strain are incorporated with a fine polynomial fitting. So, the flow stress is regarded as the function of the deformation parameters such as strain, strain rate and deformation temperature. The average activation energy for the hot deformation of the spark-plasma-sintered Ti-6Al-4V alloy was 425.581 kJ/mol. Meanwhile, hot-processing maps were established based on dynamic material modeling to obtain the regular pattern of the influence of the processing parameters on deformation. The results show that the effects of deformation temperature, strain rate and strain on the peak-dissipation efficiency factor and the instability range are extremely significant. With an increase in the strain, the peak-dissipation efficiency factor increases and the flow-instability range gradually decreases. The optimum deformation temperature and strain rate for hot working of the spark-plasma-sintered Ti-6Al-4V alloy are 950-1000°C and 1-5 s-1 , respectively.