This paper focused on studying the microstructure and mechanical properties of TA15 titanium alloy fabricated by laser additive manufacturing after normal annealing treatment and double anealing treatment. The results indicate that TA15 alloy has a super fine basketweave microstructure after normal annealing treatment

and which will change to a bi-modal microstructure with a crab-like primary α phase with super fine transformed β phase after double annealing treatment. The ultimate strength

yield strength and fatigue limit of the alloy after normal annealing heat treatment are better than the alloy’s after double annealing treatment. But the plasticity and fracture toughness of the alloy after double annealing treatment are superior to those of the alloy after normal annealing heat treatment