Abstract: The built-up eddy current pulse thermal imaging inspection platform was used to detect the surface defects of common metals. In order to remove the noise interference in the thermal image and improve the contrast of the surface defects of the metal specimen, the independent component analysis method was used to analyze the thermal response characteristics of the surface defects. The results show that the independent component analysis method can effectively identify the thermal response signal characteristics of the defect area, the coil area, the defect and the area near the coil, the edge area of the test piece, etc. The visual inspection of openings defect area is imaged clearly, and the linear defect and the small surface of the metal component are realized.