Abstract: A method of image enhancing based on Independent Component Analysis(ICA) is presented for infrared(IR) thermal images that acquired by an IR camera in the test system and always have the problem of lowcontrast and highnoise, which can effectively eliminate the noise interference of the images and enhance defect contrast. The fundamental theory of ICA and Fast ICA algorithm based on negative entropy criterion is introduced. The detailed processes of the method and results are given. The results of the experiments show that the method has higher peak signal to noise ratio(PSNR) and can improve image quality, which establishes basis for future research of image segmentation.