The OIP bushing is made of insulating paper and aluminum foil alternately wound on the conductive pipe (rod) according to the design requirements. The capacitive core is installed in the upper and lower porcelain sleeves (or composite hollow insulators) connected together through the connecting flange, and then the transformer oil is injected under vacuum to realize insulation. Since the company made the first oil paper capacitive bushing in China in 1958, it started technology introduction, understood and mastered the foreign process manufacturing technology of oil paper insulation products, thus forming its own proprietary process manufacturing technology, making the technical parameters and index level of bushing reach the first-class level of foreign similar advanced products. The electric performance and insulation margin of the products are even better than those of foreign products.