In this paper, an electrospinning technique was developed to prepare CaSc2O4: Yb3+/Er3+ one dimensional (1D) nanofibers for the first time. X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy and nitrogen adsorption/desorption were utilized to characterize the structure and morphology of the as-prepared nanofibers, indicating that single phase mesoporous CaSc2O4: Yb3+/Er3+ 1D nanofibers with a uniform size and morphology can be prepared via the electrospinning technique. The as-prepared CaSc2O4: Yb3+/Er3+ 1D nanofibers exhibit strong UCL under the excitation of 980 nm. The cross-relaxation (S-4(3/2) + I-4(15/2) -> I-4(9/2) + I-4(13/2)) and energy back transfer (S-4(3/2) + F-4(7/2) - I-4(13/2) + F-4(5/2)) processes are found to be responsible for the concentration-dependent UCL properties, confirmed by rate equation modeling. Optical thermometry in the temperature range of 298-623 K was recorded using the FIR technique with two green UC emissions in the as-prepared CaSc2O4: Yb3+/Er3+ 1D nanofibers. The dependence of the sensitivity on the doping concentration of the Yb3+ and Er3+ ions is found. The above results suggest that the as-prepared CaSc2O4: Yb3+/Er3+ 1D nanofibers have great potential for the applications of drug delivery and optical thermometers.