A high precision inspection method based on image mosaic was proposed for the final optics inspection in an Inertial Confinement Fusion (ICF). The image mosaic method contains image registration stage and image fusion stage. In the image registration stage, a registration method based on feature matching of local damaged area was used to overcome the exposure difference between the subimages and the lack of image information, and the moving information in the inspection system was used in image matching to improve the inspection precision and inspection efficiency. In the image fusion stage, the Poisson image fusion was adopted to eliminate the "stitching line" caused by an exposure difference and to implement the seamless mosaic. The images of final optics inspected by Final Optics Online Inspection (FOOI) was compared with the proposed method and Scale Invariant Feature Transform(SIFT) method,and the results show that the proposed method is superior to SIFT method. The 4×4 mosaic image shows that the inspection resolution of the FOOI device in the ICF has been improved significantly by proposed method.