Fiber Bragg grating(FBG) is widely used in hydrogen measurement because of its fast response speed and quasi distributed measurement. In order to further expand the measurement range of hydrogen concentration, an FBG hydrogen sensor based on mesoporous platinum doped tungsten trioxide(Pt/WO3) powder is proposed, and an FBG sensor head is cascaded for temperature compensation. The experimental results show that when the concentration of hydrogen is increased from 0 to 32%, the maximum drift of the central wavelength of FBG is about 320 pm, the response time is about 10 s, and there is a good linear relationship in the range of 0-14% hydrogen concentration, the sensitivity is 11.69 pm/%H2, which can realize quasi distributed hydrogen concentration sensing.