A novel measurement and digitalization system of surface defects on optical devices——microscopic scattering imaging is put forward based on international ISO10110-7 surface defects standard and inertial cofinement fusion engineering standard. The multi-beam optical fiber cold light source illuminates the detected surface whose view field is about several millimeters in a special angle. The image of bright defects in black background is formed that is suitable for digital image binary processing. The sub-aperture is detected and imaged using the X-Y scanning system. The information of full surface defects is obtained by stitching the sub-aperture images with the template matching principle. A complete digital evaluation software system of large aperture surface imperfections measurement based on morphology is presented. A group of standard reticules are fabricated by binary optics to scale defects. The resolution of the optical system of defects-microscopic scattering imaging is better than sub-micrometer and the view field of a sub-aperture is about 3 mm. An image array of 5×5 sub-aperture is obtained by two-dimensional scanning system. The full image of surface defects is reconstructed, and the quantitive comparison with the standard value is also presented. The experimental results show that the system is valid for measuring defects of precision surfaces.