On the basis of studying the transformer condition assessment, the paper put forward the monitoring framework of the transformer cooler based on the intelligent electrical grid, and developed the intelligent monitoring system of the transformer cooler based on the DCS and dual PLC. The system used the DCS and dual PLC redundancy, the intelligent controller of the motor, the system’s platform for the centralized monitoring, the environmental control system and the other advanced technology, and implemented the monitoring, remote control and status monitoring of the transformer cooling system to improve the reliability and adaptability of the transformer cooler system. The system can be applied for the intelligent electrical grid. The above technologies are innovative in the high-performance distributed bus, the integrated design of three-phase solid state relay and magnetic latching relay and the cooling technology of the semiconductor in the PLC module, and lie in the leading domestic level.