Abstract: Optical synthetic-aperture imaging is one of the most potential techniques for improving the resolution of system. U-V coverage, PSF and MTF of synthetic-aperture system were analyzed with different fill factors. They were discussed on the basis of Y-4 system. This study also generated image simulation of Y-4 system with the help of Zemax and Matlab.software, and restored the images with noise making use of Wiener filter and the modified Wiener filter. Reconstruction results of Y-4 system with different fill factors were analyzed and compared with the help of PNSR. The factors which affected the image qualities and reconstruction results of synthetic-aperture system were also analyzed. The results show that image restoration could improve the image quality of synthetic-aperture system and increase its definition, its image quantity is equivalent to a single aperture system and it can achieve the same effect as big aperture system, and the results of image restoration are dependent on the array structure of synthetic-aperture system and noise types.