The present work aims to study the deformation and failure behavior of laser powder bed fusion (LPBF) manufactured Ti6Al4V alloy. Uniaxial tension, pure shear, combined tension and shear specimens in horizontally, inclined and vertically (0°, 45° and 90°) building directions have been tested and observed by digital image correlation (DIC) technique. Significant anisotropy in ultimate strength, strain hardening and maximum elongation were observed. The failure mechanisms of 0°, 45° and 90° built LPBF Ti6Al4V alloy under different stress states are revealed by fractographical analyses. As the stress triaxiality increases from 0 to 0.33, distortion and shearing of micro voids induce the failure of shear specimen whilst void nucleation, growth and coalescence is the dominant failure mechanism of LPBF Ti6Al4V alloy under tension. The inherent defects significantly affect shear and tensile performance, large interlaminar shear deformation appears in horizontally built shear specimen, the tensile loading is prone to open the defects of vertically built uniaxial tensile sample due to the building direction. It can help to better understand the failure mechanism and improve the quality of LPBF Ti6Al4V in practical applications.