TiAl alloys possess advantages such as low density, excellent high-temperature oxidation resistance, and comprehensive high-temperature mechanical properties, making them highly regarded as lightweight high-temperature structural materials in the aerospace industry. However, the inherent brittleness of TiAl alloys at room temperature severely imits their potential for engineering applications. Consequently, improving the microstructural uniformity and grain refinement has become a research focus for TiAl alloys. The influence of deformation heat treatment parameters on microstructural evolution in cast Ti-48Al-2Cr-2Nb alloys was investigated by employing a combination of low-temperature pre-deformation and subsequent heat treatment. Additionally, in situ observations using high-temperature laser scanning confocal microscopy were employed to analyse phenomena such as recrystallization, grain growth, and lamellar precipitation in the low-temperature deformed microstructure. Starting from an initial coarse microstructure of the as-cast alloy with lamellar colonies of approximately 400 μm, fine-grained duplex microstructures with lamellar colonies and γ grain sizes of 21 and 12 μmcan be obtained through scientifically controlled low-temperature pre-deformation above the ductile-to-brittle transition temperature and subsequent heat treatment in the α+γ phase region.