Abstract: The ground state of HPuO under different electric fields ranging from －0.005 to 0.005 a.u. was optimized using density functional theory DFT/B3LYP with relativistic effective core potential (RECP) for Pu and 6-311+G* for O and H. The excitation energy was calculated under the same electric fields employing the time-dependent DFT method. The results show that the electronic state, total energy, molecular geometry, dipole moment and excitation energy are strongly dependent on the field strength of applied electric field. The dependence of the calculated excitation energy on the applied electric field strength is fitting well to the relationship proposed by Grozema. The spectra of the first five excited electrons of HPuO are in the regions of infrared-far infrared. The wavelength is in the range of 1 046.0-3 038.7 nm.