Abstract: 316 stainless steel was fabricated through selective laser melting (SLM) additive manufacturing and compared to traditionally manufactured counterparts. The microstructure and performance characteristics were assessed using metallographic microscopy, scanning electron microscopy, X-ray diffraction, and Vickers hardness testing. To investigate irradiation-induced hardening effects, 3.5 MeV Fe ions irradiation was carried in two types of 316 stainless steel at room temperature. The results indicate that the additive manufacturing 316 stainless steel displays a characteristic columnar crystal structure with a single austenite γ phase, accompanied by a high-density subgrain-like cell wall structure and the hardness exhibits anisotropy between the scanning and deposition plane. Irradiation hardening effects are observed on two types of 316 stainless steel after Fe ions irradiation, and hardening rate of the 316 stainless steel produced through additive manufacturing was found to be less significant than that of traditionally manufactured steel. Furthermore, there is also anisotropy in irradiation hardening.