Abstract:The failure rate of analog circuits has been high for a long time, but the analog circuit cannot be completely replaced by digital circuits because of its objective world signal nature. The reliability of analog circuits has become a key factor that limits the reliability of circuit systems. This article mainly studies the soft fault diagnosis method of analog circuit, analyzes the difficulties of analog circuit in fault diagnosis, and summarizes the development and research status of traditional and intelligent fault diagnosis, and forecasts the future fault diagnosis of analog circuit development trend.