In structural health monitoring, performance degeneration of optical fiber Bragg grating (FBG) sensor will seriously affect the whole monitoring system′s stability and accuracy. High temperature, high pressure and many other bad conditions may cause FBG sensor performance degeneration. Therefore, in this paper, the theory that fiber Bragg grating sensor performance degeneration caused by temperature is analyzed. Influences of different kinds of FBG sensor on performance degeneration are analyzed quantitatively by numerical simulation and temperature cycling experiment. The experimental results show that performance degeneration of FBG is related to its own reasons. For normal FBG sensors, its peak value of reflective spectrum decreases with the increasing of the cycle numbers. For FBG sensors containning some hydrogen molecules, with the numbers of cycle increasing, its peak value of reflective spectrum decreases, and its central wavelength shifts towards short wavelength.