The influence of laser process parameters on the densification, phase composition, microstructure, and mechanical properties of Ta-33wt.%Ti alloy prepared via laser powder bed fusion (LPBF) was investigated. The results show that fully dense and homogeneous Ta-Ti parts can be obtained from LPBF with appropriate energy input. The cellular and dendritic structures were formed due to constitutional undercooling. Transmission electron microscopy (TEM) analysis showed that the lamellar α″ phase within the cellular structures preferred to concentrate at the cellular boundaries owing to the elemental micro-segregation in the solidification front. The samples fabricated under the energy density of 166.7 J/mm³ had a favorable ultimate tensile strength of 806 MPa and an excellent Young’s modulus of 36.7 GPa.