The ground-state CF4 molecule was optimized using a density functional theory/B3LYP method in the 6-311++G basis set.The bond length, dipole moment, Mulliken charge population distribution, molecular frontier orbital energy and infrared were calculated.Spectral and other data, and based on this hybrid CIS method was used to calculate the first 9 excited states of CF4 molecule, and the molecular excitation energy, wavelength and oscillator strength were obtained.The study shows that as the electric field intensity increases (electric field in the range of -0.04-0.04 a.u.), the F2—C1 bond length of the CF4 molecule increases, and the remaining bond length decreases, and the dipole moment of the molecule decreases first.With the increase, the number of C1 charge population decreases first and then increases.The population of F2 charge population decreases linearly.The population of F3, F4 and F5 charge population increases linearly, and the molecular energy gap decreases.CF4 molecular structure under external electric field Symmetry is destroyed, the number of infrared absorption peaks increases, and the absorption intensity of absorption peaks changes.The first 9 excited states of the molecule are affected by the electric field.The excitation energy increases with the increase of the electric field, and then increases first and then decreases.The excited wavelength is basically a phenomenon of blue shift, followed by a phenomenon of red shift, and intense vibration of the oscillator,to make theoretical calculations for studying excited states from the spectrum.