Transformer substation automatic system is more and more developed towards the opening distributed and layered direction. And in the substation automatic system, communication is an important step. Despite the growing number of multi-agent software system and agent adapts well to dynamic physical environment, however, few power systems have adopted the technique of multi-agent. This paper adopts the technologies of multi-agent based on multi-thread to strengthen the intelligence, real-time, safety and extensibility of the system. In the meantime, this paper puts forward the method to realize the communication system of the automatic system, in which adopts the mobile-agent to realize the communication from the dispatch center to substation. In this paper we put forward a communication model which increases the real-time characteristic and reliability of the system.