The defects on TB6 titanium alloy were repaired using pulsed TIG(tungsten inert gas) additive manufacturing technology, and the effects of process parameters (pulse current and pulse time) and heat treatment on the microstructure and mechanical properties of the repaired TB6 titanium alloy were studied to determine the optimal heat treatment process parameters. The results show that the mechanical properties are relatively better in the as-repaired state when the pulse current is 50 A and the pulse time is 40 ms, with a tensile strength of 1113 MPa and an elongation of 5. 26 degrees 0. These samples are sequentially subjected to solid solution and aging heat treatment. When the samples are solid solution treated for 2 h under different temperatures (740 , 760, 780 degrees C), the primary alpha phase is increasingly dissolved, while the (3 phase gradually grows and evenly distributes in the matrix. After water quenching, the growth of the (3 phase is inhibited, and acicular rhombic martensite alpha" phase is precipitated in (3 grains, resulting in a decrease in tensile strength and a remarkable increase in elongation. Under different aging temperatures (500 , 520, 540 degrees C) for 8 h, the alpha'' phase continuously grows and gradually transforms to equiaxial grain, and the mechanical properties are greatly improved. The optimal microstructure and mechanical properties are achieved under the conditions of 780 degrees C/2 h WC+520 degrees C/8 h AC, with a tensile strength of 1119 MPa and an elongation of 7. 36%.