The invention discloses a dedicated electronic instrument transformer for an HGIS, and belongs to the technical field of instrument transformers. The dedicated electronic instrument transformer comprises a bush housing, an electric conductor, a sensing head component and a collector, wherein the electric conductor, the sensing head component and the collector are arranged in the bush housing; the sensing head component comprises a capacitance ring, a Rogowski coil and a low-power current transformer; meanwhile, the sensing head component is connected with the collector; a capacitance gas insulating medium is arranged between the capacitance ring and the bush housing; a cocurrent bus in the bush housing serves as a high voltage polar plate of a capacitance voltage divider of an electronic voltage transformer; the bush housing serves as a grounding polar plate of the capacitance voltage divider; the collector comprises a power supply module and a data processing module. The dedicated electronic instrument transformer for the HGIS has the benefits that the transformer is free of magnetic saturation, wide in frequency response range, high in precision, good in transient characteristics, free of high-voltage insulation, wide in range of temperature application and the like; the design is simplified; the transformer is connected through optical fibers, and the digital signals are transmitted through the optical fibers, so that the EMI (Electro-Magnetic Interference) resistance can be enhanced, and the data reliability is greatly increased.