The spatial distribution function of grating amplitude recorded in photorefractive crystal based on the couple-waves theory is given. The enhancement properties of holographic grating readout by single-beam and by double-side alternative readout are analyzed after solving the couple-equations numerically. A storage architecture, which includes one crystal and a dynamic holographic refresher (DHR) easily enhanced diffraction efficiency by double-side readout is presented. Meanwhile the optimal architecture parameters to realize the grating enhancement are also given.