An optical fiber temperature sensor using two fluorescent dyes based on fluorescence intensity ratiometric (FIR) method is proposed.In our experiment,Rhodamine B and Rhodamine 110,which are temperature-sensitive and temperature-insensitive respectively,act as the sensing materials.Polymer optical fibers are utilized to guide excitation light and collect emitted fluorescence.By calculating the fluorescence intensity ratio of the two dyes,the temperature can be measured.