The invention relates to a transformer or electric reactor oil temperature detecting and simulating device which is characterized by comprising a multifunctional meter (G). A first detecting terminal (G-1) and a third detecting terminal (G-3) of the multifunctional meter (G) are connected with a first output terminal (ZK-1) and a third output terminal (ZK-3) of a function switch (ZK) respectively, and a second detecting terminal (G-2) and a fourth detecting terminal (G-4) of the multifunctional meter (G) are connected with a second output terminal (ZK-2) and a fourth detecting terminal (ZK-4) of the function switch (ZK). Trial proves that after the transformer or electric reactor oil temperature detecting and simulating device is used for carrying out oil temperature detection and defect overcoming on transformers or electric reactors of 220kV or higher-voltage transformer substations, the working efficiency is greatly improved, more importantly, due to the fact that defects are timely overcome, the accuracy of device monitoring is guaranteed, a reliable basis is provided for timely observing faults, and the safety benefits are obvious.