The standard current transformer using for calibration of current transformer is ferromagnetic and multiple tap structure, which secondary side exists the high voltage danger when in open circuit. It is needed to change high side wire coils and secondary outlet terminal when measuring the accuracy of calibration. Based on the Rogowski coil electronic transformer technology, through high precision Rogowski coils and the design of multiscale control system, this paper developed the standard current transformer of 0.05 level by Rogowski coil, which can meet the accuracy calibration from 5 A5000 A in different rated primary electricity flow. By using Rogowski coil and high precision digital multirange control system, it can convert current signal into standard digital signal. Rogowski coil has not iron core, and has the advantages such as light quality、small volume, meanwhile，it also has high linearity wide measuring range, wide frequency response range and have open protocols, and it can meet the development of digital signal electronic transformer calibration accuracy requirements.