The research object is the TA18 titanium alloy rod processed by forging. Using the Gleeble-3800 thermal simulation testing machine and simulating the process of induction heating, hot compression experiments were conducted at deformation temperatures of 820~900°C, strain rates of 0.1 s-1~10 s-1, and deformation amount of 80% to investigate their high-temperature mechanical behavior. Based on the peak stress, a high-temperature plastic constitutive equation for TA18 titanium alloy was established. A dynamic material model was used to plot the thermal processing map, and a plastic instability map was constructed based on the Prasad instability criterion. The results indicate that, at a constant strain rate, the flow stress of TA18 titanium alloy decreases with increasing deformation temperature. Besides, TA18 shows positive strain rate sensitivity at a constant deformation temperature. Under conditions of strain rates of 1 s-1 or above, TA18 titanium alloy exhibits significant dynamic recrystallization behavior, demonstrating good hot workability. The Arrhenius equation can effectively predict the variation of peak stress under different process parameters for this alloy. TA18 exhibits optimal hot workability within the deformation temperature range of 860~880℃ and the strain rate range of 3 s-1~10 s-1.