The system achieves synchronous data collection and directional analysis of the additional electromagnetic oscillation signals of the transformer by applying the matrix arrangement of electromagnetic oscillation sensors, realizes the diagnosis and early warning of latent faults during the operation of the transformer, and automatically pushes operation and maintenance suggestions to avoid major damage accidents of the transformer. The grounding microcurrent module is used to promptly capture the discharge faults of the transformer. Timely identify internal and external faults of the transformer, such as winding deformation, core faults, and internal and bushing discharge faults of the transformer for monitoring and early warning. Fault monitoring and early warning for issues such as moisture or damage to the internal insulation of the transformer, multi-point grounding of the core, foreign objects in the box, and sludge deposition in the oil tank.