Base on the in-depth study of existing transformer equipment information systems, this paper proposes a transformer full dimension decision method. It realizes the real-time synchronization, .data fusion and comprehensive analysis of transformer’s multi-source heterogeneous data, and involves analytical models of transformer state assessment, fault diagnosis, risk assessment, life prediction and maintenance decision. This method can provide theoretical guidance for the transformer in its full life cycle. Moreover, this paper constructs a transformer full dimension intelligent decision support system based on the proposed method through the distributed physical architecture and intelligent agent technology. The proposed system has been applied successfully. The result indicates that the system can reflect the current state of a transformer. Meanwhile the system can provide the grid manager with theoretical guide in seeking maintenance decision strategy.