The mechanical and diffusion properties of bcc Ti-Nb-Zr-Sn alloys in the Ti-rich corner were analyzed through a high-throughput method with the combination of nanoindentation and diffusion couple techniques. Nine groups of quaternary Ti-Nb-Zr-Sn diffusion couples were prepared after annealing at 1273 K for 25 h. The composition-dependent mechanical properties were determined by nanoindentation and electron probe microanalysis (EPMA) techniques. Moreover, the corresponding interdiffusion coefficients were confirmed from the composition gradients of the quaternary diffusion couples using a pragmatic numerical inverse method. A composition-dependent database on the mechanical and diffusion properties was utilized to discuss the processability during the hot working. The results reveal that the solute elements Nb and Sn are strictly controlled to increase the hardness and wear resistance of Ti-Nb-Zr-Sn alloys, and the additional element Zr is mainly useful to improve the processability during the hot working.