The present paper is devoted to the calculating of transition wavelengths, oscillator strength, Einstein An0 and B0ncoefficients of titanium monoxide molecule from ground state to the first six different excited states by employing the density function theory BLYP and the single substitute configuration interaction approach with basis set 6-311 + + G **. The excited states of titanium monoxide molecule under different external electric fields are also investigated. It is shown that the α HOMO-LUMO gaps become smaller and the electrons of the occupied orbital tend to the virtual orbital as the external electric field intensity increases, and the β HOMO-LOMO gaps become bigger, while the variation in excitation wavelength of high-excited states turns more complicated than that of low-excited states, and the coupling strengths of excited states increase with external electric field increasing.