Abstract: The rare earth ion Er3 , Eu3 double doped LaOF phosphors were prepared by the hydrothermal-assisted solid-phase method. The phase composition, particle size, morphology and fluorescence spectrum of LaOF: Eu3 phosphors doped with Er3 at different concentrations were characterized and analyzed by XRD, SEM and fluorescence analyzer. The results show that the precursor LaF3 of Phosphors is well transformed into tetragonal LaOF after calcining at 900 ℃, and with the increase of Er3 doping concentration, the luminescent properties of the phosphors show a good rule at the excitation wavelengths of 365 nm and 393 nm. Among them, the excitation at 365 nm shows the transition from orange light to yellow light, while the excitation at 393 nm shows the transition from orange light to magenta light. Finally, Er3 , Eu3 co doped LaOF phosphor is made into ink and printed into patterns, and when it is excited to excite light at 365 nm and 395 nm, the orange and purple light emission is visible, respectively, which shows that they can be used in the field of anti-counterfeiting.