The isothermal hot compression test of TC27 titanium alloy was carried out on a Thermecmaster-Z testing system in the temperature range of 900 ℃ to 1 150 ℃ and the strain rate range of 0.01 s-1 to 10 s-1, the compress variation is 50%. The results show that the flow stress increases quickly with the augment of true strain and decreases after the flow stress reaching the maximum value.Finally,the flow stress tends to be relatively stable.The flow stress decreases with the increase of temperature and increases with the increase of strain rate. Processing map of TC27 titanium alloy exhibits two peak efficiencies of power dissipation, one is 900 ℃/0.01 s-1, which dynamic recovery occurs,and the other is 1 050 ℃/0.01 s-1, which dynamic recrystallization occurs.