Based on the electrostatic crystal field model of Faucher et al., in which the induced electric dipoles of ligands are obtained from a set of self consistent combined equations and the contributions from farther ligands are considered,the crystal field energy parameters of nano crystal X1-Y2SiO5: Eu3+ are calculated by using related data of its crystal structure and physical properties.Moreover,we successfully extend the above model to calculate the transition intensities,thus giving a theoretical luminescence spectroscopy,which approximately agree with the experimental one.Additionally,the useful wavefunctions of crystal field states are obtained in this calculation process thereby.