The invention provides a novel high-temperature Ti alloy with high heat resistance and high heat stability. The alloy contains eutectic Nb, Ta and Mo elements. Based on the appropriate proportion of these three elements, the alloy is superior in high resistance and stability to heat and good antioxidant effect. The alloy contains (by weight) Al 5.0-6.3 percent, Sn 3.0-5.0 percent, Zr 2.5-7.0 percent, Mo 0.2-1.5 percent, Si 0.20-0.55 percent, Nb 0.2-1.0 percent, Ta 0.2-3.0 percent, C 0.01-0.09 percent, and Ti and other inevitable impurities in balance. The alloy is an ideal alternative material for high-temperature parts of aircraft engine, such as wheel disk, drum barrel, barrel shaft and blade.