A new fiber Bragg grating(FBG) vibration sensor with a special structure of metal three-legged stand and elastic cantilever is designed for many low-frequency tests in engineering structures and mechanical systems.It can work with a wide band,amplify vibrating signal and increase sensitivity.And the mathematical model of vibration sensor was established.Furthermore,natural frequency,sensitivity,distortion factor,and horizontal anti-jamming capability of the sensor were measured.Experimental resu...