Ti-48Al-2Cr-2Nb alloy reinforced by in-situ Ti2AlC was prepared by vacuum arc melting. The effect of CNTs content on the microstructure evolution and mechanical properties of TiAl alloy was investigated. The results show that with the increase of CNTs, the solidification path of the alloy moves to the direction of high Al and the volume fraction of γ phase increases. Meanwhile, the lamellar structure is gradually refined, and the length-diameter ratio of Ti2AlC gradually decreases. The mechanical properties of the alloy incresase significantly under the action of solid solution strengthening, grain refinement strengthening and Ti₂AlC precipitated phase strengthening. With the increase of CNTs content, the Vickers hardness of the alloy increases from 358.4±19.2 HV to 428.5±23.1 HV. The compressive strength at room temperature and high temperature of the alloy first increases and then decreases with the increase of CNTs. When the addition of CNTs is 3.0 at.%, the compressive strength and maximum strain at room temperature reach 1890.61 MPa and 29.09%, respectively, which increase by 54.95% and 28.31%, respectively. At 800 ℃, the hardening and softening effects of the alloy are affected by the CNTs content. The alloy with 3.0 at. % CNTs shows the highest compressive strength, increasing by about 31.42% compared with without CNTs addition, and the alloy with 4.5 at. % CNTs shows better softening effect without sacrificing the compressive strength.