The oretical analysis is conducted on the typical fault problem of abnormal voltage output during the use of a certain type of single axis pendulum accelerometer. The fault tree comprehensive analysis method is used to track and analyze layers by layers, expressing the internal relationship between abnormal output voltage faults and intuitively pointing out the logical relationship between unit faults and overall faults, We have effectively summarized and summarized the problem of abnormal output voltage faults of single axis pendulum accelerometers encountered in engineering applications. Then, the cause of the fault was accurately and meticulously located, and the D4 diode positive electrode gold wire fracture in the oscillator circuit was proposed as the root cause of the accelerometer fault. The circuit gold wire fracture mechanism analysis method was incorporated, and the accuracy of this fault analysis was verified through experimental testing and improvement measures, which to some extent improved the reliability of the accelerometer. The research results can provide a certain reference for the reliable use of accelerometers.