The invention relates to a titanium alloy, in particular to a titanium alloy and a preparation method thereof. The titanium alloy comprises the following components in percentage by weight: balanced of Ti, 5.3-6.10 percent of Al, 1.80-2.20 percent of Sn, 1.80-2.20 percent of Zr, 1.80-2.20 percent of Mo, 1.80-2.20 percent of Cr, 0.13-0.19 percent of Si, lower than 0.08 percent of Fe, lower than 0.08 percent of C, not more than 0.03 percent of N, not more than 0.015 percent of H and not more than 0.12 percent of O; the smelting technical parameters are as follows: the vacuum degree before smelting is lower than 3Pa, the leakage rate within 3 min is equal to or lower than 3Pa, the smelting vacuum degree is equal to or lower than 3Pa, and the smelting current and the feeding current range from 2kA to 10kA; and the preparation method comprises the following steps: firstly, preparing the intermediate alloys AlSn50, AlCr50 and AlMo60, and then performing electrode preparation, electrode baking, electrode welding, furnace loading, smelting, cooling, furnace tapping, turning and sampling analysis by budgeting. The invention has the advantages that the refined grains of the alloy for silicon are added in, the processing and the forging are easy, the tensile strength in the performances of a plate processed by the alloy reaches 1100-1300MPa, the elongation rate reaches 12-20 percent, and meanwhile, the Beta phase can be stabilized.