Abstract: Tungsten alloy /steel bimetallic composites are widely used as key materials for kinetic energy penetrators, where they are subjected to extreme conditions involving high temperatures and high strain rates during high-velocity impact. In this study, dynamic compression experiments were performed using a split Hopkinson pressure bar at a strain rate of 10,000 s?1 to investigate the adiabatic shear behavior at different temperatures. The results show that the material exhibits pronounced temperature sensitivity under high strain rate conditions, accompanied by significant thermal softening as temperature increases. At the investigated temperatures of 298 K, 873 K and 1173 K, the dominant sites for the initiation and development of shear localization are mainly located in the steel, tungsten alloy, and steel, respectively. This variation is likely related to the different abilities of the two phases to store and release strain at different temperatures. At 873 K, enhanced dynamic recovery in the steel makes it more difficult for strain to accumulate, while stress concentration in the tungsten alloy more readily triggers shear localization. At 1173 K, the steel experiences significant microstructural reconstruction and thermal softening, which promotes the onset of thermomechanical instability. Moreover, the role of the tungsten alloy/steel interface in governing shear localization appears to evolve with temperature, shifting from facilitating strain accommodation and energy dissipation to promoting stress transfer between the two phases. Based on these observations, a comparative analysis is carried out to describe how shear localization is distributed within the two-phase material over the investigated temperature range, from the perspectives of strain evolution and interfacial response.