The electronic structures of Ti-Al alloys with Cr, V addition were studied using the first-principle pseudopotential plane-wave method. The total energy, cohesive energy, mechanical property, the charge density and density of states of the alloys were calculated, and the reason that the mechanical property was improved after Cr, V infiltration in Ti-Al alloys in terms of theory was explained. The results show that with the alloying elements Cr (0-25at%), V (0-25at%) content increasing, the absolute value of cohesive energy of the alloys becomes larger and the structure is more stable; the values of shear modulus G and Young’s modulus E increase, but the increment gradually decrease. The main reason is that the addition of Cr in the alloys enhances reciprocal hybridization of Cr 3d, Al 3p and Ti 3d, while V in the alloys enhances reciprocal hybridization of V 3d, Ti 3d and Al 3p, and the alloys’ binding capacity is increased.