Er³⁺, Na⁺ co-doped CaF₂ transparent ceramics with Er³⁺ dopant concentration of 3% and Na⁺ of 0%, 0.5%, 1.0%, 1.5% and 2.0% were fabricated by the vacuum hot pressing method with 16 mm in diameter and 3 mm in thickness. The average grain size of the obtained Er, Na∶CaF₂ powders varied from 28 nm to 36 nm with the shape of sphere. The effects of Na⁺ doping on the transmittance, microstructure and spectral properties of Er³⁺∶CaF₂ transparent ceramics were investigated. The transmittance of all the obtained ceramic samples is above 84% in the wavelength of 1 000 nm. The results show that after introducing Na⁺ into Er³⁺∶CaF₂ transparent ceramics, charge-neutralized Er³⁺-Na⁺ structure formed which prevent Er³⁺ from clustering. The emission spectra of Er³⁺ in CaF₂ transparent ceramics at around 1.5 and 2.7 μm could be modulated by adjusting the concentration of Na⁺ and the near-infrared fluorescence lifetime at around 1.5 μm increase with the increasing of Na⁺ concentration, reaching a maximum of 56.75 ms.