The invention relates to a short time, high temperature and high strength titanium alloy and a preparation method thereof and belongs to the field of titanium alloy materials. The titanium alloy comprises, by weight, 6.3%-7.5% of Al, 1.5%-3.5% of Sn, 4%-5% of Zr, 0.8%-1.5% of Mo, 4.5%-7% of Nb, 2%-4% of W, 0.2%-0.5% of Si and the balance Ti, wherein the sum of the Nb and the W is 6.5%-10%. A Ti-Al-Sn-Zr-Mo-Nb-W-Si ingot is formed by smelting through a vacuum consumable electric arc furnace, and hot rolling is conducted to obtain a finished bar. The titanium alloy is subjected to multi-element reinforcement by adding the Al, Sn, Zr, Mo, Nb, W and Si, and especially the adding amount of the Nb and the W is high, so that the high-temperature strength and the endurance property of the alloy are improved, and the application requirement for the titanium alloy under the condition of short time, high temperature and high strength at the temperature of 650 DEG C or above can be met.