The invention provides a preparation method for a large-specification TC4 titanium alloy ring piece. The preparation method comprises the following steps that (1) TC4 titanium alloy blanks are heated to a technical temperature and subjected to heat insulation, and the forging operations of two-upsetting and two-drawing are conducted; (2) the TC4 titanium alloy blanks are heated to the technical temperature and subjected to heat insulation, the operations of upsetting and punching are conducted, and a TC4 titanium alloy circular blank is obtained; (3) the TC4 titanium alloy circular blank is heated to the technical temperature and subjected to heat-insulation and then the broaching operation is conducted; (4) the TC4 titanium alloy circular blank is heated to the technical temperature and subjected to heat-insulation, and rolling operation is conducted; (5) the TC4 titanium alloy circular blank is heated to the technical temperature and subjected to heat-insulation, and after the TC4 titanium alloy circular blank is reshaped, air cooling operation is conducted; and (6) the TC4 titanium alloy circular blank is subjected to annealing treatment, and the large-specification TC4 titanium alloy ring piece with the external diameter being 720mm-1300mm is obtained. The large-specification TC4 titanium alloy ring piece prepared through the method consists of the alpha equiaxed phase and the beta transformed tissue, the microstructure is uniform and small, and the large-specification TC4 titanium alloy ring piece does not have an original beta crystal boundary and has high strength and good plasticity.