Based on distributed artificial intelligence,the paper put forward MAS based distributed intelligent malfunction diagnosis method and process,and discussed pattern-clustering based malfunction solution-finding mechanism and the identification and decomposing of a diagnosis task.It also studied the restriction and relationship of multi-agent in the macroscopic sense,and designed the expression mechanism for applied agent's work status.Else it ascertained the influence and the communication and the interaction among applied agents,and constructed a multi-agent fuzzy related model.The last aspect is that the paper presented an integrated descriptive structure of local diagnosis decision and global diagnosis decision,and established a distributed agent diagnosis system structure and its prototype model system too.Diagnosis system can be divided into applied agent and service agent,using distributed communication mechanism to realize intercommunication of information,realize distributed system s information exchange and diagnosis,and enhance system's efficiency,security and error standing for problem-dealing.When the model was applied in the power enterprise's security monitor system the result was similar to expert system,and the model overcame many deficiencies of previous monitor diagnosis system,enhanced the efficiency of the enterprise security running.