This study is prompted by the reality that the forging velocity greatly impacts the phase transformation of titanium forged parts, further affecting the ultimate microstructures and mechanical properties of their final parts. In this paper, to predict the transformation characteristics of temperature and phases in Ti-6Al-4V drum hot forging procedure, a simplified FE model embedded with phase transformation equations is developed and verified by experiments. Then, based on two evaluation indexes, the effect of forging velocity on the transformation characteristics of temperature and phases within the forged drum is analyzed quantitatively. The results suggest that unlike little effect on lamellar alpha+beta phase, appropriately enhancing the forging velocity can increase the general levels of temperature and beta phase and improve the uniformities of temperature, alpha phase, and beta phase distributions within the forged drum.