The fluorosilicate glass was prepared by a conventional melt-quenching method, namely Er3+/Yb3+: SACF. The structure of Er3+/Yb3+: SACF glass was characterized by XRD, FTIR, and Raman spectra. According to the absorption spectra and Judd-Ofelt (J-O) theory, the spectral intensity parameter (Ωλ) were obtained, Ω2 = 4.16 × 10−20 cm2, Ω4 = 1.13 × 10−20 cm2, Ω6 = 0.86 × 10−20 cm2, and compared to the parameters in other glass host matrix. The radiative properties including spontaneous transition probability, fluorescence branching ratio, and a radiative lifetime of Er3+ ion in Er3+/Yb3+: SACF glass were calculated by J-O theory. And the excitation and emission spectra were recorded to characterize the luminescence properties in the visible region. In the near-infrared region, the emission spectra were obtained excited by a 980 nm laser. Also, under the excitation of a 980 nm laser with different pumping power, the up-conversion emission spectra of Er3+/Yb3+: SACF glass was tested, and a possible up-conversion luminescence process in the Er3+/Yb3+ system was analyzed. Finally, the up-conversion luminescence color and chromaticity coordinates were depicted by the CIE1931 chromaticity diagram.