为了提高产品的可靠性，并且在电子设备发生故障时迅速地确定故障源，保障设备的正常运行，基于多信号流模型的诊断建模方法，在多信号流基础上引入了以故障重要先验知识为主的多信号流故障诊断策略，通过引入故障模式的故障概率改进了多信号流诊断技术。该方法已应用于BEPCⅡ磁铁电源接口控制设备故障诊断系统，使用TEAMS测试工具箱建模实现了快速准确的故障诊断和定位，提高了磁铁电源控制设备的故障诊断检测率和隔离率，并且可以方便地扩展到其他设备和系统上。

In order to improve product reliability, and to quickly identify the source of failure when the electronic equipment breaks down, thus to protect normal operation of the equipment, this paper introduces the diagnosis modeling method based on the multi-signal flow model, and then develops the multi-signal flow fault diagnosis strategy, which is based on the important prior knowledge of the fault, thus improves the technique of multi-signal flow diagnosis by introducing failure probability of the fault mode. The method is then applied to BEPCⅡ magnet power interface control equipment fault diagnosis system by using TEAMS toolbox modeling, which realizes rapid and accurate fault diagnosis and positioning, improves the diagnosis ability of magnet power control equipment, and can be easily extended to other devices and systems.