In this paper,based on the analysis of the high temperature resistance of differently coated fiber bragg grating (FBG),a high temperature sensor with exc ellent accuracy and repeatability is proposed,and its packaging structure and temperat ure measurement performance are experimentally studied.According to the different s tate of FBG,two types of packaging structures for the FBG high temperature were designe d and studied,where the FBGs are in free state and bonded state,respectively.It is revealed that the polyimide fiber grating is suitable for the high temperature monitoring.Consequ ently,such a kind of FBG was selected for annealing optimization and packaging treatment.The experimental results show that different package structure has a great influence on the temperature measurement performance of the sensor.The linear fitting degree of 0.9999in the free state of FBG is better than that in the paste state.The precision of t he FBG high temperature sensor using this package structure reaches ±0.5℃,and it is suita ble for high temperature measurement.