Abstract: The high-throughput diffusion-multiple technique and thermodynamics databases were used to design new high-strength Ti alloys. The composition-microstructure-property relationships of the Ti64-xMo alloys were obtained. The phase fraction and composition of the α and β phases of the Ti64-xMo alloys were calculated using the Thermo-Calc software. After aging at 600℃, the Ti64-6Mo alloy precipitated ultrafine α phases. This phenomenon was explained on the basis of the pseudo-spinodal mechanism by calculating the Gibbs energy curves of the α and β phases of the Ti64-xMo alloys at 600℃. Bulk forged Ti64-6Mo alloy exhibited high strength and moderate plasticity after α/β-phase-field solution treatment plus aging. The tensile properties of the alloy were determined by the size and morphology of the primary and secondary α phases and by the β grain size.