This work aims to investigate the selective laser melting (SLM) process of TA7 ELI on the density through analyzing the influence of process parameters such as laser power P and scanning speed V. The influence of laser energy density on defects was further analyzed, and the microstructure and mechanical properties were analyzed based on the optimal forming process parameters. Results show that the density of TA7 ELI formed by SLM firstly increases and then decreases with the increase of laser power P and laser energy density. When the laser power P is 280 W, the scanning speed V is 1 000 mm/s, the scanning spacing H is 120 μm, and the coating thickness t is 30 μm, the highest density of the formed sample is 99.89%, and the corresponding laser energy density is 78 J/mm3. TA7 ELI formed by SLM shows epitaxial columnar crystal growth along the deposition direction and equiaxed crystal structure along the direction perpendicular to the deposition direction, which is composed of fine needle-like α′ martensite with parallel or staggered distribution. The as-deposited tensile strength of material is more than 1050MPa and the elongation rate reaches 15%. The tensile fractures are evenly and densely distributed with equiaxed dimples, showing typical ductile fracture characteristics.