In order to let the CCD recording and the reconstruction of the Fresnel hologram run well

a algorithm of numerical reconstruction is designed. Fresnel digital hologram is recorded directly with a CCD target instead of a conventional holographic plate on in-line configuration

and stored as a BitMap file in the computer. A real image of the original object can be reconstructed from the hologram by the numerical method instead of the optical diffraction. The paper deals with an experimental design of the in-line holographic recording with a CCD and the algorithm of numerical reconstruction and the un-destructibility of the digital hologram are verified with a computer program.