Based on super-resolution imaging theory, a beam scanning super-resolution digital holographic technique is proposed. Applying Fresnel diffraction theory, this technique is proved to enlarge the equivalent dimension of CCD and increase the cutoff frequency of optical system, so this method can improve the imaging resolution of digital holography. The simulation verify the validity and feasibility of this method. The method of hologram processing and reconstruction is summarized. Compared with synthetic-aperture digital holography, the proposed technique needs not to move CCD camera and change the angle of reference waves that correspond to different CCD camera position for avoiding under-sampling.