A CuSnTi alloy is the key material for the preparation of Nb3Sn superconducting wires by the bronze method. Coarse grains and anti-segregation occurred in the Cu-15Sn-0.3Ti alloy prepared by conventional casting, which cannot meet the requirements of high elongation of Nb3Sn wires. In this work, the recrystallization of a Cu-15Sn-0.3Ti alloy was successfully induced by adjusting the process parameters of arc melting and hot extrusion composite processes, and a high-Sn content Cu-15Sn-0.3Ti alloy with fine equiaxed grains and good mechanical properties was prepared by using the idea of thermal-mechanical synergistic strengthening. The results show that under thermal-mechanical synergy, the coarse dendrites in the as-cast Cu-15Sn-0.3Ti alloy evolve into fine equiaxed crystals, the tin-rich phase in the dendrite gap dissolves, and the microstructure of the alloy transforms into a single α phase. The ultimate tensile strength of the alloy reaches 387.2 MPa, and the elongation reaches 42.5%, which exceeds the performance indices of imported CuSn alloys.