In order to acquire and monitor the low-frequency vibration signal, a two-dimensional vibration sensor with a symmetrical circular flexure hinge is designed, which can work in the x and z axes. The mechanical characteristics of the sensing structure are analyzed theoretically. The model is established in Comsol for simulation analysis, and the structure is optimized by finite element method. The hinge resonant frequency is designed to be 420 Hz. The fiber Bragg grating is pasted on the surface of the hinge structure as a strain detection device, and the dynamic demodulation of FBG is realized by the edge filter method. The performance of the sensor is tested with a standard shaking table. The experimental results show that the natural frequencies of the sensor in the x and z axes both are 420 Hz, the operating frequency range is 20-300 Hz, the average sensitivity in the flat region is 1847.32 mV/g, and the acceleration resolution is 5.41×10^-4 g. The sensor demonstrates a less than 5% lateral interference level in all two-dimensional orientations. The sensor designed in this paper is a two-dimensional vibration sensor, which is suitable for highly sensitive detection of low-frequency vibration signals.