Abstract: Low carbon steel tube is usually used in circulating water of the heat exchanger in service with the process medium. Normally, there exist mainly scouring corrosion and scale corrosion. In the case of tube wall being seriously thinned due to corrosion the burst might occur and the normal operation of the heat exchanger would be affected. So far the most effective and rapid method for the heat exchanger tube inspection is to use the eddy current testing technology(ET). For corrosion induced wall thickness thinning of low carbon steel tube the remote field eddy current testing technology（RFT)can accurately measure the thickness value, and this can determine the residual life of the tube. The above-mentioned method can be used to monitor the equipment and provide a reference basis for the technical innovation of the heat exchanger.