Abstract: Taking the titanium-copper mixed powders as raw materials, the high-performance Ti-3Cu（wt%） alloy was fabricated by using selective laser melting（SLM）, then the heat treatment was carried out at 800 ℃, 1000℃ for 2 h and air cooling, respectively. The microstructure evolution and mechanical properties of the SLMed Ti-3Cu alloy and the alloy after1000 ℃ heat treatment were mainly studied. The results show that the microstructure of the SLMed Ti-3Cu alloy is uniform.Under rapid cooling conditions, lamellar α fine-grain structure is formed in Ti-3Cu alloy, and there is significant accumulation of copper at the grain boundaries and Ti₂Cu band is precipitated, which has a pronounced interfacial pinning effect. The Ti₂Cu band and the intragranular Ti₂Cu nanoparticles significantly enhance the tensile strength of the alloy. After 1000 ℃ heat treatment of Ti-3Cu alloy, the grains grow up, the Cu element segregation at the grain boundary forms a large amount of brittle hard Ti₂Cu phase, which makes the strength decrease. When the Ti-3Cu alloy is treated with 800 ℃, the stress concentration during SLM is effectively reduced, and no large amount of Ti₂Cu is precipitated at the grain boundary, the strength decreases and the plasticity increases compared with those of the SLMed sample.