Abstract: Electronic spectroscopy is an important technique to explore the valence electronic configuration and coordination behavior of actinide ions. In theory, calculations for the energy levels of excited-states may directly provide information about the electron transitions and corresponding spectroscopies of actinide ions. However, the complex relativistic effect of valence electrons of 5f and 6d orbitals makes it difficult for using those developed computation methods to accurately describe the electronic configurations of actinides. In order to obtain a suitable method for calculating the energy levels of the excited-states of actinides and the electron transitions between the correlated states, the absorption spectra of the tetravalent uranium hydrate were calculated with 11 distinguished computation methods, and compared with the experimental absorption spectra of U(ClO₄)₄ in 1 mol/L HClO₄ solution to systemically evaluate those methods. Calculation methods varied from time-dependent density functional theory (TDDFT) to multi-reference perturbation theory (MRPT), with both Douglas-Kroll-Hess（DKH） method and effective core potential (ECP) method adopted to deal with the scalar relativistic effect. Seven 5f orbitals and five 6d orbitals were included in the active space with spin-orbital coupling (SOC) effect considered during the electron transitions. The simulation results show that TDDFT calculation level is inadequate for accurate simulations to the excited-states of actinides, and ECP+SOC matrix method is also unsuitable to deal with the relativistic effect during electron transition. However, the complete active space self-consistent filed integrating with the n-electron valence state perturbation theory (CASSCF+NEVPT2) method combined with DKH2+SOC matrix can well describe the properties of excited-states of aqua U⁴⁺, but with slight overestimate to the transition energy. After 0.29 eV redshift, the calculated adsorption spectrum can well agree with the experimental UV-Vis spectrum in both transition energy and absorption strength. By comparing spectrum peaks and transition patterns to theoretical spectral terms of 5f² electronic configuration, it is found that the calculated 90 excited-states and 1 ground state are perfectly correlated to 91 micro-states of the 13 theoretical spectral branches. The number of excited-states to each absorption peak is completely consistent with the degeneracy of each spectral term, and the spin multiplicity of the excited-state is also consistent with the spectral multiplicity. Thus, the reliability of the selected calculation methods can be evaluated and validated by assigning the absorption bands to the corresponding electron transitions of actinides ions. This study demonstrates a benchmark route for the absorption spectra simulation to the actinides.