Due to the low density, high strength and excellent high-temperature performance, γ-TiAl alloys are new lightweight high-temperature structural materials with good application prospects. γ-TiAl alloys can partially replace Ni-based superalloys, which have been used in hot end parts of aircraft engines, such as low-pressure turbine blades and valves, automotive engine exhaust valves and other hot end components. With the rapid development of modern industry, the service environment of high-temperature components in the future will become increasingly harsh, and it will be a challenge to exceed the service temperature of existing γ-TiAl alloys and improve their mechanical properties. In this paper, the solidification characteristics of cast γ-TiAl alloys and recent research progress on grain refinement are reviewed. The characteristics of the solidification behavior and corresponding microsegregation behavior of the alloy are discussed. At the same time, to solve the problems of microsegregation and refine the grain size, the grain refinement methods for γ-TiAl alloys are summarized in detail. Finally, a new method of grain refinement with a metastable microstructure is introduced, and the problems faced by the existing refining methods are described, which can provide guidance for the production and development of γ-TiAl alloys.