Abstract: In response to the problem of low sensitivity of fiber Bragg grating (FBG) in temperature measurement applications, this paper proposes a new solidification sensitization method based on an EpoCore adhesive-coated FBG sensor with a high thermal expansion coefficient. A FBG sensor model was constructed using COMSOL software, and the deformation of the grating area before and after sensitization was simulated. The results showed that EpoCore adhesive sensitization increased the deformation of the FBG sensor by about 10 times compared to before sensitization. Using ultraviolet exposure technology to write FBG onto thulium tin co-doped optical fibers directly and conducting in-depth research on the solidification process of EpoCore-coated FBG sensors, the resonant peak of the solidified and sensitized FBG exhibits good linearity with temperature drift when baked at 120 ℃ for 2 hours, irradiated with ultraviolet light for 5 hours, and baked at 120 ℃ for 3 hours. The temperature sensitivity is 90.45 pm/℃, about 9 times higher than the unsolidified and unsensitized FBG sensor. The sensitized FBG sensor is used to measure environment temperatures of −20 ℃, 30 ℃, 60 ℃ and 100 ℃, and the RMSE for these temperatures is less than 1.3 ℃. Compared with traditional metal coating and polymer coating packaging methods, EpoCore adhesive has a more significant sensitization effect, which provides a new idea for the application of FBG sensors in temperature measurement.