Based on the research of corrosion resistance coupon, a new method has been proposed, which uses the lowsignal relay G6K2PY to realize the multichannel measurement of corrosion resistance coupon. A kind of corrosion resistance coupon containing 4pcs of resistance specimens, can realize the multichannel switch measurement whether the resistance specimens are exposed or inclosed. And the measurement resolution of this system can reach the level of 1μΩ.