In order to adapt to the application of optical fiber sensor in high s peed mechanical equipment safety monitoring,a kind of double-fiber-Bragg-grating (FBG) symmetrical high-frequ ency acceleration sensor is designed and a novel FBG matched demodulation method is proposed.The structure and working principle of sensor are demonstrated,and the theoretical calculation and finite e lement method are used to analyze static and dynamic characteristics of the sensor.Finally the sensitivity,the amplitude-f requency response characteristics and transverse anti-jamming ability of the accelerometer are tested experimentally. The matched FBG demodulation principle based on the ratio method is analyzed,which can eliminate the impact o f the LED instability on the measurement accuracy.The experimental results show that:the sensor resonant fr equency is 900Hz,the sensitivity is 88mV/g and the measurement value of acceleration is up to 80m/s ², which is basically consistent with the theoretical calculation and finite elemen t analysis results;the transverse sensitivity coefficient is less than 10%,and the sensor has a good anti-interference ability.