Aiming at the problems of low sensitivity and large diagnosis error in power operation and maintenance fault detection in the existing technology, a new fault diagnosis scheme is designed. In this scheme, the PID fuzzy control calculator is combined with the big data algorithm model, and the real-time wiring method is used to reduce the diagnosis area. Based on the improved big data algorithm model, the fault data characteristics of power operation and maintenance equipment are extracted, the diagnosis network is constructed for the operating conditions of power operation and maintenance equipment, and the data diagnosis is completed by analyzing the functional system of the operating conditions of power operation and maintenance equipment. In order to reduce the diagnosis error, a fault diagnosis equipment is designed in this study. The integrated chip design and algorithm program are adopted to reduce the volume and ensure the accuracy of the detection results at the same time. The experimental results show that the fault diagnosis error of this research method is small, and the highest accuracy is 98.6%.