MEMS is believed as a most promising technology in future. DHM is a powerful technique to characterize the behavior of MEMS. In the reconstruction process of a digital hologram, aberrations always exist, which is always removed by the software installed in the computer. We propose a method to obtain an aberration free digital hologram. The optical arrangement is presented to verify the possibility of our method, which is then improved by a space-fiber hybrid system. The system is flexible and useful in designing a practical digital holography microscope.