The BMH empirical potentials of Pu-O bond in α-Pu2O3 are fitted by GULP program. The structure and optical properties of PuO2 and α-Pu2O3 crystal are calculated by molecular statics and molecular dynamics using BMH and shell potentials. The result shows that their simulated space groups, cell parameters, densities and entropies are approximately the samc as the data in published papers, with relative error less than 1.2%. Furthermore, their static （high frequency） dielectric constant tensor, IR dielectric function spectra and crystal lattice vibration peaks are all calculated. Part of the results are validated by experiment of spectroscopic ellipsometry, and the indirect energy bandgap of PuO2 is found to be 2.1 eV.