In order to enhance the temperature sensitivity of fiber Bragg grating (FBG),a bi-metal FBG temperature sensitivity enhancing device is designed.Based on the difference between the thermal characteristics of two different metals and a smart sensitiv ity enhancing structure,the device can enhance the temperature sensitivity of FBG obviously. The characteristics of the device are analyzed theoretically and the wavelength to temperature respo nse is calculated. Highly temperature-sensitive FBG sensors are produced by fixing FBG on the temp erature sensitivity enhancing device.To make the fixed point stable in a long per iod,the FBG is fixed by using low melted glass technology.The highly temperature-sens itive FBG sensor is tested and the result indicates that the temperature sensitivity is increased to 345.9pm/℃,as 35times of that of bare FBG,and the linear degre e is 0.99989.The temperature sensitivity enhancing device has little impact on the power of refle cted light wave and the shape of reflected spectrum of the highly temperature-sensitive FBG sensor, compared with the unpackaged FBG.A stability test is carried on and the result indicates that the stability of the highly sensitive FBG sensor is nearly the same as that of the b are FBG in a long period.