A novel deformable Ti-43Al-3.5Mn-0.5W (at.%, the same below) alloy was designed and fabricated. The microstructure characterization, room and elevated temperature tensile mechanical properties, anti-oxidation resistance, and deformation capacity were investigated. The results indicate that compared with Ti-42Al-5Mn, the developed alloy has better strength, high temperature anti-oxidation resistance and thermal deformation ability. The α2 and βo phases of the novel alloy have lower Mn content, which reduces the precipitation tendency of Mn-rich Laves phase at near service temperature. The evolution of the phases in the alloy can be generalized as follows: β→β+α→β+α+γ→β+βo+α+α2+γ→βo+α2+γ, with the Tγ-solv≈1250℃, Tβ≈1360℃. The microstructure of the alloy after heat treatment is lamellar structure and a large number of βo and γ mixed phases at the lamellar interface. Through two-step heat treatment, the high temperature strength and stability of the forged alloy are improved to a certain extent, which is mainly attributed to the increase of lamellar structure content and the refinement size of lamellar colonies. At 800℃, the yield strength, tensile strength, and elongation of the forged alloy treated with 1260℃/30min/AC+800℃/3h/FC were 320 MPa, 555 MPa, and 16%, respectively