In order to solve the problem of the excessive current and low precision in micro-resistance mea? surement at present, a design for the micro-resistance measuring system of the low measuring current is intro? duced. Taking the constant current source with high precision as current source, the precision amplifying circuit based on a operational amplifier ICL7650 and OP07ADJ with very low drift and low noise，through the real-time data acquisition and A/D converter, the data are processed and displayed by MCU, and the magnify principle of the weak signal and the feasibility of the measurement are analyzed. The experiment shows that the micro-resis? tance is precisely measured under the low measuring current, the measuring accuracy reaches 1/1 000 when the measuring resistance is 0.05 ~0.5 Ωand the measuring current is 5~10 mA.