Four TiAl alloys with different Mo contents were designed, and the microstructure and mechanical properties of these Mo-TiAl alloys were studied by scanning electron microscope, nanoindentation, and hot compression simulation methods. Results show that with increasing the Mo content, the content of γ phase is gradually decreased, while that of β phase is gradually increased. The Mo element mainly exists in the form of β phase in the TiAl alloy. During the hot isostatic pressing process, the Mo element is diffused from the γ and α₂ phases to the β phase. The nanoindentation hardness of Mo-TiAl alloy reaches the maximum when the Mo content is 1.59at%, and it is negatively correlated with the interlamellar space. As the content of Mo element increases, the flow stress of Mo-TiAl alloys decreases, and the TiAl alloys with 2.11at% and 3.94at% Mo addtion have poor plasticity due to the Al element segregation.