With the development of optical technology, higher requirements have been put forward for optical components. The accuracy and veracity of detection is an important part of optical components. The registration of defective images is a very important link. Therefore, it is necessary to study the registration of defective images. Aiming at the defect image registration algorithm, the principle and process of SIFT algorithm based on feature point matching are introduced. The experimental platform is programmed by MATLAB software to obtain the defect image. The defect image is registered and mosaic by SIFT algorithm, and the complete defect image is obtained. The experimental results show that the algorithm can effectively register the defect image and lay a good foundation for the subsequent defect information extraction.