β-solidifying titanium aluminium (TiAl) alloys are promising high-temperature structural materials and have great potentials in applications of the aviation, aerospace, and automobile industries. The phase transformation process of β-solidifying TiAl alloys from the molten state to room temperature is complex and directly affects their processability and performance. This article summarizes the major phase transformation types with respect to β-solidifying TiAl alloys, including β→α, β→β0, α→α+γ→α2+γ,and β0/α2→ω0.The effects of alloying elements, external stress and cooling rate on the microstructure and properties of β-solidifying TiAl alloys have been elaborated on the basis of the research progress of related mechanisms. The challenges and fundamental issues that need to be addressed for the industrial application of β-solidifying TiAl alloys are also discussed.