It is important to carry out accurate and reliable temperature measurements for daily life, industrial production and scientific work. The non-contact temperature sensing technology has attracted extensive attention, and recent work on the optical temperature sensing of rare-earth ions doped upconversion luminescent materials becomes popular. This review represented the optical temperature measurement mechanism of the upconversion materials, the latest research work of rare-earth element ions doped upconversion phosphors and upconversion glass ceramics in the field of optical temperature sensing and other functional applications based on optical temperature sensing. In addition, the future development trend was also prospected based on the research achievements and existing problems of rare earth upconversion luminescent materials in the field of optical temperature sensing.