The three-phase two-element combination transformer is composed of two single-phase fully insulated voltage transformers composed of three-phase V/V wiring, two current transformers are connected in series on phase A and C respectively, using epoxy resin and high-temperature vulcanized silicone rubber composite insulating pillar structure, its surface creepage distance is large, the umbrella skirt is adopted, and the high-temperature silicone rubber material used outside has good hydrophobicity, which greatly improves the pollution lightning voltage and can effectively prevent the occurrence of pollution flash failure; It has anti-aging and anti-tracking performance, and the electrical erosion performance reaches the 1A 6.0 level of the first grade in the GB6553-1986 [equivalent to IEC587 (1984)] standard, and can continuously withstand pollution and lightning pressure; It has the characteristics of strong mechanical impact resistance, not easy to damage, and long maintenance cycle; The nameplate is a white steel plate, anti-corrosion and anti-rust; The secondary terminal is sealed with a white steel metal cover, which can be rainproof, dustproof and corrosion-proof. The current conversion ratio is poured in a conspicuous position on the surface of the transformer, which can prevent the theft of electricity by replacing and changing the method of changing the transformation ratio of the sign, and also brings convenience to the supervision and inspection work of the power consumption department; The secondary end cover screws are equipped with sealing holes, which can be sealed with lead seals to avoid power theft caused by switching the secondary line, which is an ideal replacement product for power grid transformation and anti-theft transformation.