With the development of power system, Conventional current transformers (CTs) show a growing number of shortcomings. For better performances, Electronic Current Transformers (ECTs) are researched to replace CT. But high price, unsatisfactory life and unpredictable reliability hold back their industrializations. Employing the insulation structure of traditional inverted SF6 transformers and the new sensing principle at the same time, using high-precision digital integration algorithm which has higher precision to extracting the power frequency signal, an innovative electronic current transformer is introduced in this paper. Test results show that the transformer has high accuracy, low price, good stability, wide frequency response and long life.