The invention provides a mutual inductor device in an intelligent substation. The mutual inductor device comprises a low-power iron-core coil, a primary converter, a capacitive voltage divider, a composite insulator, an optical fiber, an insulating optical interface module, an optical cable, a driving module and a merging unit; the low-power iron-core coil and the primary converter are arranged at the high-voltage end of the mutual inductor device; the merging unit is connected with secondary equipment of the substation; the merging unit is used for receiving multi-channel sampling signals transmitted by the primary converter, merging and synchronously processing the multi-channel sampling signals, and generating multiplexed output. The mutual inductor device in the intelligent substation is simple, reliable, small in size, light in weight, large in dynamic response range, and free of magnetic saturation, a PT does not have a resonance phenomenon, and precision is unrelated to loads.