The flow stress behavior of powder metallurgy (PM) Ti-47Al-2Nb-2Cr alloy during hot deformation was investigated at temperature of 950-1150_oC and strain rates of 0.001-0.1s_-1. In this paper, the influence of deformation parameters on the critical conditions of the dynamic recrystallization behavior was studied systematically. Based on the analysis of flow stress curves under different hot processing parameters, the critical strain (ε_c) and critical stress (σ_c) were obtained with the help of the critical condition theory proposed by Poliak and Jonas. It is also shown that the critical condition model was established by employing the strain rate and temperature compensation factor (Z): ε_c=1.2×10_-3Z_0.147. The occurrence of dynamic recrystallization behavior will be promoted with the increase of deformation temperature and the decrease of strain rate. Moreover, the reliability of the established model was verified by the observation of deformed microstructure.