Abstract: This paper presents an extrinsic Fabry-Perot (F-P) cavity optical fiber temperature sensor, which is based on the frequency-modulated continuous-wave laser interference. The temperature sensing probe is fabricated by a stainless-steel tube with high coefficient of thermal expansion to encapsulate the F-P cavity. Stainless steel tube is used as the F-P cavity and also the temperature sensitive component. The variation of cavity length caused by thermal expansion of F-P cavity is measured by frequency-modulated continuous-wave interferometric measurement technique. The experimental results show that the temperature measurement resolution of the fiber temperature sensor reached 0.0002 ℃ and the temperature measurement sensitivity reached 3022 nm/℃. The temperature sensor not only has high sensitivity and resolution, but also has a simple and stable structure and a good application prospect.