Abstract: In order to study the influence of galvanometer accuracy on selective laser melting forming parts, Ti6Al4V samples were prepared under three different galvanometer accuracy, and the hardness, density, phase, microstructure, mechanical properties, and fracture morphology of the parts were analyzed. The results showed that the phases of the three groups of samples were all α/α', and the density, Vickers hardness, yield strength, and strain values of the samples decreased as the galvanometer accuracy deteriorated. When the galvanometer calibration accuracy was within 0.025 mm, the fracture strain of the tensile specimen was 10.15%, and the marking line did not show significant deviation. When the galvanometer calibration accuracy was within 0.05 mm, the fracture strain of the tensile specimen was 8.99%, the marking line did not show significant deviation, and the edge of the fracture showed inclusions, while the surface of the part showed small pores. The tensile strength and yield strength changed insignificantly, but the elongation after fracture decreased. When the galvanometer calibration accuracy was within 0.09 mm, the fracture strain of the tensile specimen was 8.37%, and some marking lines deviated by 10 μm. The surface of the part showed obvious large pores, and inclusions appeared on both sides of the fracture. The tensile strength changed little, the yield strength decreased slightly, and the elongation after fracture decreased significantly. It was analyzed that within a galvanometer calibration accuracy of 0.05 mm, the melting track during the printing process did not show significant deviation. Within a galvanometer calibration accuracy of 0.09 mm, some printing points showed drifting phenomena, causing the melting track to deviate and deviate from the original planned path, resulting in the generation of pores, splashing, or unmelted powder, which reduced the density of the parts and the bearing area of the tensile specimens, leading to a decrease in the elongation after fracture.