A direct production method of high-strength titanium alloy from upgraded titania slag (UGS) was developed. First, UGS was reduced into alloy powder with 1.3 wt.% oxygen using magnesium powder. Subsequently, the alloy powder was compacted at 600 MPa to produce a pellet. Lastly, the pellet was sintered to produce titanium alloy. The reduced powder was characterized, and the effect arising from the sintering temperature on the sintered density, compressive strength, microstructure, and hardness of the alloys was studied. The results showed that the density tended to increase with the temperature increasing from 900 to 1200 °C, whereas the porosity decreased. A significant sintering densification was achieved at the temperature above 1100 °C (98.65% at 1100 °C and 99.41% at 1200 °C). At 1100 °C, the hardness and compressive strength reached the maximal values of the alloy, HV 655.7 and 1563 MPa, respectively.