Using MPW1PW91/Aug-cc- PVTZ method and basis set, the physical properties of OH molecule under different electric fields were obtained, including the bond length, energy, vibration frequency, infrared spectrum, dipole moment, potential energy function and so on. Results show that with the increase of electric field, the energy decreases continuously, the frequency increases first and then decreases, and the dipole moment increases monotonously. The infrared spectrum has a blue shift. When the electric field is absent, the stimulated wavelength is located in the ultra-violate region, there is no energetic degeneration, the strength of oscillation is also influenced strongly, and some forbidden spectra are also stimulated up. Therefore, the electric field has a great influence on UV-VIs absorbing spectra. The Morse potential function is simulated, and the parameters are consistent with the values among experiments and literature. The electric field also declines the depth of potential of OH molecular, which makes the dissociating energy of OH molecular lower.
