The filtering characteristic of acousto-optic tunable filter (AOTF) is very sensitive to the change of the ambient temperature, so the ambient temperature can be obtained from the changing central frequency of AOTF′s filtering characteristic. Using the idea, a novel temperature sensor based on AOTF is fabricated. The temperature range measured by the new temperature sensor is from -40℃ to 150℃, and the precision can be up to 0 001℃. Furthermore, a kind of distributed temperature sensors to supervise and control the temperature of many distributed sites at a central place can be developed. The novel temperature sensor has an important application in the precise and distributed temperature sensor field for these advantages.