The oxyfluoride tellurite glasses doped with Dy3+ions, Tb3+ ions respectively and co-doped with Dy3+ ions and Tb3+ ions were synthesized by high-temperature melting method. Densities of different molar concentrations of Dy3+ions and Tb3+ ions were measured. Transmission spectra, excitation spectra, emission spectra and decay time were investigated. And the energy transfer between Dy3+ ions and Tb3+ ions were studied. The results showe that all the glass samples have a high density with more than 5 g·cm－3, and up to 6.09 g·cm－3. Dy3+ ions can effectively sensitize the luminescence of Tb3+ ions, when molar concentrations of Dy3+ ions is more than a certain concentration, the emission intensity of Tb3+ ions will be decreased because of the concentration quenching effect. With 1mol% Dy3+ ions, the emission intensity of Tb3+ ions show higher for 6mol% Tb3+ ions - doped oxyfluoride tellurite glasses. Based on Dexter theory, it is showed that the energy transfer between Dy3+ ions and Tb3+ ions was nonradiation energy transfer by analyzing the analyzingenergy level diagram and energy transfer from Dy3+ ions to Tb3+ ions.