Capacitive acceleration sensor with acoustic cavity

The invention provides a capacitive acceleration sensor with an acoustic cavity, comprising a sensor frame, an acceleration detection structure composed of a detection quality block and an elastic vibrating diaphragm, and a back plate with damping holes and limit embosses, wherein, the detection quality block is arranged at the center of the acceleration sensor and is connected with the sensor frame by the surrounding elastic vibrating diaphragm; the damping holes manufactured on the back plate are used for adjusting system damping, and the limit embosses are used for preventing adhesion or damage in the case of overload; the detection quality block is parallel to the back plate, and detection capacitances are respectively formed on the opposite surfaces of the detection quality block andthe back plate; and the fact that the sensor frame is internally provided with an acceleration detection structure and internally formed with the acoustic cavity after the back plate is closed can improve frequency response. The sensor structure of the invention has lower requirement on the vacuum degree of the acceleration sensor, and can adjust important parameters such as a quality factor Q and the like which can adjust a system by changing density and size of the damping holes and volume of the acoustic cavity and the like, thus realizing larger flexibility on design and manufacture.