Abstract: The thermal deformation behavior of double-phase titanium alloy BT22 were studied in the temperature range of 750-850 ℃ and strain rate range of 0.001-1 s-1 by using thermal simulation tester, thermal processing maps of the alloy were built and the best isothermal forging zone was confirmed. The results reveal that the obvious dynamic recrystallization characteristics were exhibited on true stress-true strain curves of double-phase titanium alloy BT22; Two domains in the thermal processing maps were steady, their centers located at (750 ℃,0.001 s-1) and (850 ℃,0.001 s-1), and their maximum power dissipation rate was more than 50%. The zone with temperature range of 750-850 ℃ and strain rate range of 0.01-0.001 s-1 may be considered as the optimum isothermal forging zone of the tested alloy.