Abstract: This paper presents an eddy current array technique to detecting the delamination detect of aluminum sheet. The simulation using Ansys software and experimental verification were performed to investigate the impact of process parameters, defect size and depth on eddy current signals. The flat bottom holes with different aperture and depth were employed to simulate the delamination defects. .The results showed that there was the highest sensitivity when the nominal frequency of eddy current array probe was used. Within the defect diameter range of 8-12mm, for the constant defect size, with defect depth decreasing the induced voltage increased and phase lag angle deceased; for the constant defect depth, the defect size had little influence on the phase angle. So the delamination defect depth can be determined through the induction signal.