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The surface plasmon resonance of copper in the near infrared region provides a novel method for enhancement of up-conversion luminescence compared to using gold and silver, as the former grants significant cost savings. In this study, we made a flat Cu film covered TiO₂ to enhance the up-conversion fluorescence intensity. The results show that the deposition of copper/TiO₂ dioxide nanocomposite film prepared via spin-coating has no effect on the structure of NaGdF₄:Er³⁺, Yb³⁺. The absorption wavelength of the copper film moved from the original visible wavelength (~600 nm) range to the infrared wavelength after covering TiO₂, and most obviously, the copper film covered two layers of TiO₂ by about 16 nm; the peak of the absorption appeared at 835 nm due to the enhanced excitation field. The behavior of the nanocomposite film with NaGdF₄:Er³⁺ and Yb³⁺ under 980 nm excitation was investigated; it provides a novel way for studying mental-enhanced fluorescence. Besides, the peaks of the fluorescence spectrum show different emissions at 542 nm and 660 nm, respectively. The copper nanoparticles-covered TiO₂ layer can obviously enhance the fluorescence intensity, and the maximum enhancement factors of emission of NaGdF₄:Er³⁺ and Yb³⁺ nanoparticles are 3.1 and 1.9 on the nanocomposite film, respectively.