Based on the density functional theory, using the first principles pseudopotential plane wave method to calculate Co, Cr doped and Co, Cr Co doped rutile TiO2 band structure, density of States and optical properties. The results show that: the band gap of pure rutile is 3.00 eV, Co doped rutile TiO2 band gap of 1.21 eV, the conduction band and valence band top bottom are located in the G spot, is a direct band gap between the valence and conduction band, the impurity level by Co 3d and Ti 3d hybridization; Cr doped rutile TiO2 direct band gap of 0.85 eV, the impurity levels between the valence and conduction band by Cr 3d and Ti 3D orbital track structure, the conduction and valence bands are moving toward low level direction, Also, it is doping modification of ion selective basis; Due to the strong hybrid electron, make the O-2p state and the Ti-3d state to the Co-3d state and Cr-3d mobile of Co-Cr Co-doped, the valence band energy shifts to a higher energy level and the bottom of the conduction band energy level shift to lower energy, so greatly reducing the band gap width. The dielectric peak doped rutile TiO2, refractive index and absorption coefficient all shift to lower energy; In the range of E<2.029 eV, pure rutile imaginary part of dielectric function, k and absorption coefficient is zero, the transition strength after doping is higher than the transition intensity of undoped zno, Transition intensity of Co, Cr Co-doped is greater than Co doped and Cr doped, Co, Cr Co-doped can strengthen the electron optical transitions in the low end, visible light catalytic performance has better.