Abstract: The Cu-Ti alloy has the same level of mechanical properties and electrical conductivity as Cu-Be alloy. It also has good high temperature properties and stress relaxation resistance. Therefore, it is a promising material to replace toxic Cu-Be alloy. With the development of high technology, the new generation of connector materials put forward higher requirements for performance, such as strength greater than 1000MPa and conductivity greater than 15% IACS. However, it is difficult to obtain Cu-Ti alloys with high strength and such high conductivity. Generally, the effective way is to increase the aging temperature or prolong the holding time of the alloy. On the one hand, the strength of the alloy is reduced, on the other hand, the increase of cost is inevitable. In addition, refining grains or regulating the size and distribution of precipitates is a better means, which is also true for Cu-Ti alloy. At present, the refined grain size is still 10~60μm through a series of common processing methods including hot rolling, solid solution and cold rolling. Therefore, the improvement of strength and conductivity is limited for Cu-Ti alloy. This paper provides a preparation method for synchronously improving the strength and conductivity of Cu-Ti alloy. The Cu-3Ti-0.1Mg-0.05B-0.05La alloy with ultra-fine grain structure is obtained by vacuum casting and cold billet opening process. At the same time, the secondary aging process is used to adjust the size and distribution of the second phase, so as to obtain Cu-Ti alloy strip with high strength and good conductivity. The results show that the Cu-3Ti-0.1Mg-0.05B-0.05La alloy has a maximum microhardness of 356HV and a conductivity of 14.5% IACS after aging at 400℃/2h. The relationship between the second phase precipitation and properties of Cu-3Ti-0.1Mg-0.05B-0.05La alloy was analyzed by TEM. The evolution of the second phase is Ti rich phase → the granular phase β′-Cu4Ti phase → the granular β′-Cu4Ti phase + lamellar β-Cu4Ti phase → the lamellar β-Cu4Ti phase. The granular β′-Cu4Ti phase is the most important strengthening phase, the lamellar β-Cu4Ti phase can decrease the strength of the alloy, but increase the conductivity. The comprehensive properties of Cu-3Ti-0.1Mg-0.05B-0.05La alloy can be further optimized by the secondary aging process. The microhardness and electrical conductivity of the Cu-3Ti-0.1Mg-0.05B-0.05La alloy reach 341HV and 20.5% IACS after primary aging at 450℃/8h +50% cold rolling + secondary aging at 400℃/1h.