Abstract: In order to improve the detection sensitivity of eddy current testing technology on the surface and near surface of copper clad steel, an eddy current testing probe of copper clad steel was designed from the perspective of coaxiality correction and probe parameter optimization, which will clarify the influence of variables on detection sensitivity, such as the coaxiality state of probe and copper clad steel, the frequency of excitation signal, the number of turns of probe coil, and the width of probe. With the numerical simulation technology, the influence of the coaxiality between the probe and the copper clad steel on eddy current detection was theoretically confirmed. Moreover, a special detection probe with adjustable diameter for copper clad steel was designed and manufactured, which can identify the near-surface defects with a depth of 0.1 mm in copper clad steel. The orthogonal experimental method was used to study the influence of different factors on the eddy current detection probe. It turns out that the probe has the highest detection sensitivity for copper clad steel defects when the excitation frequency of the eddy current detection probe ranges from 25 to 35 kHz. The research shows that the sensitivity of eddy current testing of copper clad steel can be improved by optimizing the probe structure and the probe parameters.