Micro selective laser melting (μSLM) has huge potential in high-quality and high-precision manufacturing of near-net-shape parts made of Inconel 718 superalloy. However, few studies investigate the optimization of μSLM parameters and mechanical properties of μSLMed materials. In this study, Inconel 718 fabricated via different parameter sets were analyzed, and a comparison on microstructure, mechanical property, and machinability between the optimal μSLMed material and the material fabricated by conventional SLM (cSLM) was implemented. It is found that the smallersized grains due to the higher cooling rate of μSLM (2.1×10⁶ K/s) contribute to higher strength (1009 MPa, increased by 2.4%) and poor machinability. The low quality of cSLM material are ascribed to the application of larger laser spot and coarse powder. Vibration during the milling process is obvious due to the defects. Results of this study develops an optimal processing window for the μSLM of Inconel 718, reveals the relationship among processing parameter, microstructure, mechanical property, and machinability, which provides fundamental knowledge for the optimization of μSLM.