Abstract: The preparation, microstructure, and mechanical properties of the Ti6Al4V titanium alloy scaffolds by extrusion molding 3D printing were systematically investigated by universal testing machine and scanning electron microscope in this paper. The preparation of titanium alloy scaffolds using polyvinyl alcohol (PVA) hydrogel was introduced, the influences of slurry PVA content, degreasing temperature, and sintering temperature on the preparation process were investigated, and the relationship between the porosity and mechanical properties of titanium alloy scaffolds was analyzed. The results show that, the PVA hydrogels can be used to prepare the titanium alloy scaffolds to obtain the porous structures with uniform distribution and high interconnectivity. The optimal preparation process is obtained, when the slurry PVA mass fraction is 15%, and the degreasing and sintering temperatures are 360 and 1300 ℃. The titanium alloy scaffolds with the porosity of 59.8% exhibit the excellent mechanical properties matching human bones to avoid the stress-masking effect.