In order to obtain a stable measurement of temperature changes and improve the characteristics of a FBG temperature sensor, the packaging technology and sensing properties of fiber grating temperature sensors with preload were studied. Theoretical temperature sensing and stress distribution on the optical fiber grating temperature sensor were analyzed using finite element simulation, and the cross-sensitivity between temperature and fiber grating strain was solved. This package has certain desensitization and a greater range of temperature measurement. The epoxy DP420 adheres fiber grating with preload to the cylinder with beryllium copper material. The sensing properties of the FBG temperature sensor in the oven were studied in a constant temperature blast from 40℃ to 120℃ at intervals of 5℃. The experimental results showed that the temperature sensitivity coefficient of the optical fiber grating temperature sensor was 23.81 pm/℃, which was two times that of the bare FBG sensors, with linearity greater than 0.999.