Abstract: Hot rolled Cu-0.1Ni-0.5Cr alloy was treated with solution treatment at 960 ℃×1 h and 460 ℃ for different time. The effects of different aging time on the microstructure and properties of Cu-0.1Ni-0.5Cr alloy were studied by OM, SEM, hardness test and electrical conductivity test. The results show that with the increase of aging time, the hardness of Cu-0.1Ni-0.5Cr alloy increases first and then decreases, and the electrical conductivity increases first and then basically remains unchanged.The hardness and conductivity of Cu-0.1Ni-0.5Cr alloy aged at 460 ℃×4 h reach the peak value of 122.6 HV and 79.5%IACS, respectively. A large number of second phase precipitates in Cu-0.1Ni-0.5Cr alloy aged at 460 ℃ for different time.With the increase of aging time, the number of second phase gradually increases, and the second phase merges and grows.The optimal aging process of Cu-0.1Ni-0.5Cr alloy is 460 ℃×4 h.