Carbon steel materials are widely used in various pipelines in nuclear power plants. However, due to long-term exposure to high temperatures, high pressures and corrosive environments, their surfaces are susceptible to stress corrosion cracking (SCC), which is not easy to detect because their lengths and angles change during SCC expansion. Array eddy current detection technique (AECT) is used for SCC detection, and the probe structure consisting of one excitation coil and five receiver coils is designed to improve the sensitivity to defect lengths and angles. Firstly, the signal of different receiver coils to the lengths and angles are discussed based on simulation, and superposition process is performed on the characteristic signals. Secondly, an experimental platform is built to identify defects of different sizes on the surface of carbon steel. The experimental results show that the designed coil effectively detects changes in defect angles. By superimposing the characteristic signals from multiple receiver coils, it compensates for the limitations of individual coil detection capabilities, enhancing sensitivity and signal contrast. Consequently, this approach contributes significantly to evaluating defect lengths and angles.