Rare earth luminescent materials have gradually become a research hotspot in fluorescence anti-counterfeiting because of their high purity of luminous color, long fluorescent life, stable physical-chemical properties, and low toxicity. A series of NaGdF4∶Yb3+/Eu3+ microcrystals co-doped with various Li+ concentrations were synthesized by the hydrothermal method in this paper. The samples morphology, size, and up-conversion luminescence properties were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), up-conversion emission spectroscopy, and fluorescence lifetime tests. The crystal with strong luminous intensity was further applied to anti-counterfeiting identification. It shows that all the diffraction peaks of NaGdF4∶Yb3+/Eu3+/Li+ microcrystals are consistent with the standard-NaGdF4 card. No impurity peak was found in the XRD pattern. The hexagonal NaGdF4∶Yb3+/Eu3+/Li+ with high purity and crystallinity was synthesized. The SEM image of the crystal shows that the generated sample is a pure hexagonal phase, with uniform distribution, and no reunion. Co-doped Yb3+/Eu3+/Li+ has little effect on crystal structure, morphology and size. It can be seen from the up-conversion emission spectrum that the green luminescence intensity of 15 mol% Li+ doped NaGdF4∶Yb3+/Eu3+ crystal is 6 times higher than that of the undoped Li+ sample. Adjust the power range of the laser to 0.8～2.2 W and observe the change in UCL intensity of the samples doped with 0 mol% Li+ and 15 mol% Li+. It can be observed that with the increase of pump power, the up-conversion intensity gradually increases. The number of photons required to generate the up-conversion luminescence n is close to 2, indicating that the emission process of the sample is a two-photon process. The fluorescence lifetime of the 5D1 level in the sample is about 1.4 times that of the undoped one. Finally, the NaGdF4∶0.2Yb/0.02Eu/0.15Li crystal with uniform morphology and strong luminous intensity was further applied as fluorescent ink. Screen printing technology printed The fluorescent anti-counterfeiting patterns on paper, glass and plastic. The pattern emitted bright green light under the pumping of a 980 nm laser. In the natural environment, the anti-counterfeiting pattern on the paper has good concealment. The word “safe” lenght is 5.5 mm, and the spacing between letters is 0.5 mm. The boundaries between letters are clear and easy to distinguish under 980 nm excitation. The plastic printed with the anti-counterfeiting pattern was exposed to the outdoor natural environment for a month, and the pattern did not change significantly. It shows that the anti-counterfeiting pattern made of NaGdF4∶0.2Yb/0.02Eu/0.15Li has a high resolution, is easy to identify, and is less affected by the environment, and has excellent application prospects in anti-counterfeiting identification.