In order to measure low-frequency and small signals,a fiber grating ( FBG) acceleration sensor based on an L-shaped cantilever beam is proposed,and theoretical analys is is carried out, and its sensitivity and resonance frequency expression formula are deduced.In o rder to obtain the optimal parameters of the structure,a simulation analysis was carried out accor ding to the theoretical formula and the simulation curve was obtained.According to the simu lation curve,the various parameters of the sensor were selected,and the actual sensor was produc ed,and the sensor sensitivity amplitude-frequency response,linear response and lateral anti-int erference performance were tested respectively.The experimental test shows that the senso r resonance frequency was 280Hz.After filling with silicone oil damping,the measurement ba ndwidth is 1Hz－240Hz,and the flatness is within ±1.5db in the response curve within th e measurement bandwidth,the sensitivity can reach 52pm/g,and the linear correlation is 99.97%,which is in good agreement with the theoretical resonance frequency of 290Hz and the sensit ivity of 59pm/g, indicating the correctness of the theoretical analysis.At the same time,the se nsor has a good lateral anti-interference performance,which is 4.2%.Research shows that this s ensor can be applied to vibration test in low frequency and small signal occasions.