Based on the cross-sensitivity of fiber Bragg grating(FBG) temperature sensor, a new encapsulation method of high sensitivity of FBG temperature sensor is proposed. By setting a spring in the metal tube, the temperature was measured with pressure isolated. The purpose is to enhance the temperature sensitivity coefficient of FBG and to eliminate cross-impact of stress. Through experiments, the temperature characteristics and stress impact of packaged FBG are introduced. The results show that the wavelength offset is only caused by the change of temperature which is not influenced by the peripheral pressure. Meanwhile, the packaged FBG has good linearity and repeatability, which can be used to monitor temperature accurately.