<p>To improve the mechanical properties of 316L stainless steel, Al₃Ti with low density, high strength and excellent high temperature resistance, has been used to reinforce 316L stainless steel, prepared by selective laser melting (SLM). The microstructure, phase composition and mechanical properties of Al₃Ti/316L stainless steel composites have been investigated by optical microscope, scanning electron microscope, Powder X-ray diffraction equipment. The results show that Al₃Ti/316L stainless steel composites show the same cellular structure as in SLM-316L stainless steel composites, and a very small second phase can be observed on the surface of the cellular structure. After adding 1% Al₃Ti powder, the phase of the matrix was transformed from austenite single phase to austenite and ferrite dual phase. When Al₃Ti is more than 2 wt.%, only the ferrite phase can be observed in the XRD pattern of the specimen. Compared with the properties of 316L stainless steel, when the mass fraction of Al₃Ti is 1.0 wt.%, the yield strength of Al₃Ti/316L stainless steel composites is increased by more than 20% and the plasticity is varied slightly. When the mass fraction of Al₃Ti is increased to 3%, the yield strength of the sample is nearly twice times that of the 316L stainless steel with plasticity obviously decreased. The tensile strength is also increased from 919&#xa0;MPa (1.0 wt.%) to 1261&#xa0;MPa (3.0 wt.%). And the reinforcement mechanism of 316L stainless steel with Al₃Ti has been discussed.</p>