PECT is widely used in aviation, nuclear power, etc. In this paper, PECT integrated with Gradient Magnetic Field Measurement (GMFM) is proposed particularly for imaging of hidden corrosion in this paper.Simulation results indicate that GMFM is advantageous in detection of defect edges, which has potential benefit for defect imaging. A PECT system has been built. Signals are obtained when the PECT probe scans over a hidden corrosion, and defect images are derived in post processing. It has been found from the experimental results that the GMFM-based PECT has advantages over conventional PECT in terms of high sensitivity and efficiency in defect imaging of hidden corrosion.