Aiming at the problems of low collection efficiency and insensitive fault diagnosis in the working process of the power user’s electricity information collection system, a new design of the power user’s electricity information collection system was carried out, and its key technologies were studied. In this study, a power user electricity information collection system including terminal equipment layer, gateway interface layer, front-end processor and front-end processor application layer was constructed, and a data collector based on the STM32F103RBT6 chip was designed, which can realize the external communication of a variety of data. Improved data collection capabilities. And designed a new collection system fault diagnosis method, data fusion and fault diagnosis of various measurement data information such as smart electric energy meters, metering field monitoring equipment, collection terminals and various sensors, and improved the ability of data diagnosis. Experiments show that the method of this study has high collection efficiency, good fusion and strong fault diagnosis ability.