As high-strength and high-elasticity copper alloys, copper-titanium alloys are characterized by excellent strength, thermal conductivity, high-temperature stability and stress relaxation resistance and are considered ideal materials for replacing beryllium bronze. However, the differences in the physical properties of titanium and copper are significant, and the solubility of Ti in Cu at room temperature is limited. The microstructure segregation of the copper-titanium alloy is severe, and many coarse primary phases are inevitable, which restricts the improvement in strength and electrical conductivity. In this study, ultrasonic-assisted solidification was used to prepare a copper-titanium alloy, and the influence of ultrasonic power on the microstructure of the copper-titanium alloy was systematically discussed. The microsegregation is improved, the grain size and primary phase size are significantly refined, and the content of the Ti-rich phase is reduced after ultrasonic treatment. Under the same thermomechanical treatment, the tensile strength of the copper-titanium alloy increases from 801.38 MPa to 851.0 MPa, and the electrical conductivity increases from 15.31%IACS to 15.68%IACS. The simultaneous improvement in the mechanical and electrical conductivity properties is directly related to the refinement of the grain size and the reduction in the content of the primary phase under ultrasonic treatment.