In order to solve the problem that the accuracy of 0.3 A low current output is low in the verification of high precision gateway watt-hour meter
a low current output scheme based on trans-resistance negative feedback is proposed
and the feedback measurement module and noise filtering unit are designed
a low current standard power source is developed. The experimental results show that the designed small current standard power source is stable and reliable
and the problem of verification and tracing of small current points in 0.3 A and above gateway meter is solved.