A high-sensitivity fiber temperature sensor based on enhanced Vernier effect is proposed. The proposed sensor consists of a cascaded Fabry-Perot interferometer （FPI） and Sagnac interferometer （SI）. The FPI was a PDMS cavity formed by filling polydimethylsiloxane （PDMS） into hollow-core fiber （HCF）， and SI was formed by fusing a section of Panda fiber inside a single-mode fiber ring. FPI and SI have opposite temperature responses. With increasing temperature， the interference spectrum of FPI will red-shift， whereas that of SI will blue-shift. Therefore， when FPI and SI are cascaded， an enhanced Vernier effect will be generated， with a temperature sensitivity much greater than FPI or SI alone. The magnification of the enhanced Vernier effect is significantly larger than that of the ordinary Vernier effect. Experimental results show that the sensitivity of the sensor is -57.85 nm/℃ in the temperature range of 36–39℃， which is 44.8 and 30.8 times that of FPI and SI alone， respectively. The sensitivity magnifications are 2.56 and 1.66 times those of ordinary Vernier effect， respectively. The sensor has the advantages of high sensitivity， good stability， low preparation cost， and very good application prospects.