In order to segment and recognize the defects in C/C component，an infrared image processing algorithm based on C-V model and mathematical morphology is presented.First，an original image was de-noised by wavelet threshold de-noising method to improve the SNR of the image.Then，the de-noised image was segmented based on C-V model.The contours of defects were also detected by canny operator.Finally，mathematical morphology methods were used to smooth the contours and to remove isolated pixels outside the contours.The areas of the defects were also calculated.The results show that the defects are well segmented with this algorithm and that the calculation errors are within 6%.The very vague infrared images can be well processed with this algorithm.The contours of defects are also well detected with high locating accuracy.