Rogowski coils is a kind of special structure hollow coils, it has good linearity, no iron core, no magnetic saturation phenomenon and wide measuring range, which has been used to measure all kinds of various changes current. The current transformer consist of PCB Rogowski coil and digital integrator has been designed, includes the structure of PCB Rogowski coils and the principle digital integrator based on AD7742. The test of PCB current transformer show that it has high accuracy and PCB coils has good linearity. It can meet the requirement of current measurement.