Smelting method of high-homogeneity TC21 titanium alloy

The invention provides a smelting method of a high-homogeneity TC21 titanium alloy. The smelting method comprises the steps that raw materials are selected according to components of a TC21 titanium alloy cast ingot, and a consumable electrode is prepared; the titanium-tin alloy is clamped in the middle of the consumable electrode, and then the consumable electrode is put into a vacuum consumable electric arc furnace to be smelted for the third time, so that the high-homogeneity TC21 titanium alloy is obtained. According to the invention, the titanium-tin alloy containing the low-melting-point element Sn is pressed in the center of the electrode block, the small-particle titanium-molybdenum alloy and aluminum-niobium alloy containing the high-melting-point elements Mo and Nb are used, and the argon-filled smelting is adopted during the third smelting to reduce the volatilization of the volatile element Al; therefore, the TC21 titanium alloy cast ingot which is high in homogeneity, good in surface quality, fin