TiAl alloys are considered attractive structural materials because of their low density, excellent high-temperature strength, and oxidation resistance. However, their intrinsic characteristics, including low-temperature brittleness, poor workability, and narrow processing window, restrict their wide use in industrial applications. Various hot-work processes are conducted to enhance the inherent ductility of TiAl alloys, especially hot-pack rolling. In this work, the hot processing maps at different strains were developed based on isothermal compression tests and dynamic material model (DMM). The optimum hot-working parameters were selected and a crack free Ti-46Al-8Nb (atomic fraction, %) sheet was directly fabricated by hot pack rolling from ingot. Moreover, microstructure evolution and hot deformation behavior of the as-rolled alloys were investigated. The processing maps showed two typical dynamic recrystallization (DRX) domains which would facilitate the hot-work process, of which the temperature was at 1200 ℃, strain rates was 1 s^-1 with a peak efficiency of power dissipation of 0.38 and temperature of 1150~1200 ℃, strain rate of 0.01 s^-1 with a peak efficiency of power dissipation of 0.45. The instable-area temperature was 1100~1200 ℃ and strain rate was 0.06~1 s^-1 at low strain, which was expanded to low strain rate with the increasing strain. As the strain increased to 0.4, the region with the temperature of 1250 ℃ and strain rate of 0.006 s^-1 always became instable. The Ti-46Al-8Nb alloy sheet with thickness of 0.85 mm was produced within processing windows of 1150~1200 ℃, 0.01~0.03 s^-1 with engineering strain 18% per pass. The produced sheet showed uniform microstructure as a whole, though the local flow softening and deformation bands were inevitable. Furthermore, the main softening mechanism of Ti-46Al-8Nb alloy was DRX which began with the pile-up of dislocations, the formation of sub-boundaries and mechanical twins. Then the substructures would rearrange to inducing the formation of DRXed grains with the cumulative reduction increasing. The phase transitions of Lamellae (α/γ)→γ+α+B2/β and α→γ during hot-pack rolling combining with the growth of DRXed grains were simultaneously a main softening mechanism. The formations of plentiful mechanical twinning and twin lamellae also contributed to the uniformity of as-rolled microstructure.