Abstract: A temperature model of fiber acoustic sensors based on fiber Fabry-Perot cavity was proposed, according to the principle of Fabry-Perot interference with low fineness. The temperature model was mainly arranged with the relationships between the interference spectroscopy and temperature, and between the output of the sensor and temperature. According to the model, simulation and experiments results show that, the key factor affecting the temperature characteristics of the sensor is attributed to the difference of the expansion coefficient of materials. To overcome the effects of temperature, a composite fiber ferrule was proposed. A composite ferrule with large expansion coefficient was designed to compensate the length change of fiber Fabry-Perot. This can improve the temperature adaptability of the sensors. The fiber Fabry-Perot cavity acoustic sensor with composite fiber ferrule was tested. The experimental results show that, it can work well in the temperature range of-20~+40℃.