Ca5(PO4)3F:Yb3+/Er3+ glass ceramics (GCs) were successfully manufactured via traditional controlled crystallization method. The structural, optical and up-conversion (UC) illuminant properties were systemically investigated by XRD, TEM, HRTEM, fluorescence spectra and luminescence lifetime measurements. The results show that Ca5(PO4)3F:Yb3+/Er3+ nanocrystals has been precipitated from the precursor glass matrix and the UC luminescence mechanism of PG and GC660 is two-photon process. The enhanced UC emission intensity and extended lifetime of Er3+ is observed in the GCs. Using the temperature dependent fluorescence intensity ratio (FIR) of thermally coupled emitting states (4S3/2, 2H11/2) as thermometric index, Ca5(PO4)3F:Yb3+/Er3+ GCs present wide temperature-sensing range (298–798 K) and high absolute sensitivity (51.9 × 10−4 K−1 at 600 K). This finding suggests that Ca5(PO4)3F:Yb3+/Er3+GC materials are promising in optical temperature measurement field.