NbTiTa/Cu superconducting wires were prepared through the thermal diffusion using NbTi sheets and Ta sheets as raw materials. During the process, the rolling and drawing methods were applied after three times extrusion. The superconducting property was measured by the standard method at 4.2 K in High Magnetic Field Laboratory in France. The results indicate that a higher critical current density is obtained in the drawing wires. Jc can reach 791 A/mm2 at 4.2 K and 8 T in the drawing wires with diameter of 1.0 mm. The investigation of microstructure shows that the homogenous filament, homogenous Cu/Sc ratio and same spacing between filaments are found in the drawing wires at the same conditions