The invention relates to a high-strength high-elasticity titanium alloy and a preparation method thereof. The alloy comprises the following components of, in percentage by weight, 30%-32% of Nb, 4%-6%of Zr, 2%-3% of Mo, 0.038%-0.088% of Fe; 0.016%-0.037% of Cr, 0.005%-0.011% of Ni and the balance titanium; the preparation method of the alloy comprises the following specific steps of carrying outmechanical ball milling on titanium powder and absolute ethyl alcohol in a ball milling tank and a ball milling system composed of 0Cr18Ni9, and then performing SPS sintering on the titanium powder toobtain titanium sintering block containing trace Fe, Cr and Ni oxides; smelting flaky sintered titanium, titanium sponge, Nb, Zr and Mo raw materials in an electric arc furnace to obtain an alloy ingot; carrying out hot forging on the cast ingot into a bar material and carrying out solid solution treatment, and then carrying out cold rolling deformation processing; and finally, carrying out agingheat treatment, so that the alpha phase with the extremely fine nanometer size is separated out from a beta-precipitation matrix body. The obtained titanium alloy has high strength and high elastic performance, is low in elasticity modulus and high in elongation rate, is very suitable for manufacturing high-elasticity parts in the fields of aerospace, machinery and the like, and can also be applied to the preparation of biomedical implants.