The invention belongs to the field of titanium-based alloys, and specifically relates to a novel heat-resistant titanium alloy and its processing and manufacturing method and application, including components such as alloy composition, smelting, thermal processing and heat treatment. The composition (weight percentage) of said alloy is Al: 5.4%~6.3%; Sn: 3.0%~5.0%; Zr: 2.5%~6.4%, Mo: 0.0~0.96%, Si: 0.25%~0.5%, Nb : 0.2%~0.5%, Ta: 0.3%~3.4%, W: 0.2%~1.6%, C: 0.0~0.07%, O≤0.17%, Fe≤0.03%, the balance is Ti and unavoidable impurity elements . The alloy of the present invention can obtain different matchings of tensile strength and plasticity, durability and creep strength and thermal stability through different thermal processing and heat treatment process combinations, and can be used to make blades, discs and other parts of high-temperature parts of advanced aero-engines, It can be used for a long time in the range of 600-650°C; it can also be used to make high-temperature resistant structural parts such as aerospace vehicle skins, and it can be used for a short time at about 700°C; it can also be used as a material for high-temperature and corrosion-resistant valves for automobiles and boilers.