Abstract: Aiming at the problems of unclear accelerometer fault location test method, long period and inaccurate location, the fault mechanism of accelerometer is studied and verified in this paper. Firstly, by analyzing the structure, working mechanism and test environment of the accelerometer, the common fault modes such as positive and negative saturation and no output of the accelerometer are studied theoretically; secondly, through fault mechanism analysis and more than 20 kinds of test simulation, the corresponding fault mode of each kind of fault is established; the results show that each fault of accelerometer has a unique correspondence with the test index. With ±1 g output, positive and negative static current I+ and I-, sensor characteristics, torquer characteristics, the accelerometer fault causes can be quickly mapped. To improve the adaptability and responsiveness of the accelerometer, the accelerometer should be restored, repaired or replaced according to the cause of the failure. This study can be used for fast fault location of quartz accelerometer in model application, and can also provide theoretical basis for the optimization and improvement of accelerometer design and process.