Titanium alloy is a kind of difficult-to-machine material, which needs to seek an efficient processing method. In this paper, the deposition samples of TB6 titanium alloy were prepared by laser deposition manufacturing. The internal microstructure of the as-deposited was analyzed by Optical Microscope(OM) and Scanning Electron Microscope(SEM). The formation mechanism of interlaminar bands and the variation law of microhardness were studied. The microstructure of TB6 titanium alloy prepared by laser deposition is composed of most equiaxed and a small part of original β grains elongated along the deposition direction and approximately ellipsoidal. The original β grains are mainly composed of primary α phase(α_p), grain boundary α phase(α_GB) and matrix β phase. The temperature fluctuation between the deposition layers in the laser deposition process leads to the change of α_p phase size, which forms the layer band distribution with different contrasts.