This paper discusses the intelligent multi-agent technology, and proposes an intelligent multi-agent based Accurate fault location detection and fault diagnosis system applied in 10kv automatic blocking and continuous power transmission lines along the railway, Agents are software processes capable of searching for information in the networks, interacting with pieces of equipment and performing tasks on behalf of their owner(device). Moreover, they are autonomous and cooperative. Intelligent agents also have the capability to learn as the power supply network topology or environment changed. The system architecture is proposed, the features of each agents are described. Analysis brings forth the merits of this fault location and diagnosis system.