A method of the zero-order-removal off-axis digital holographic reconstruction by recording three holograms with different beam ratios is presented. The zero-order-removal hologram can be constituted using two fitting coefficients in the combination of three holograms, in which the three off-axis holograms with different intensity ratios of the object and reference beams are recorded via arbitrarily turning a half-wave plate. The validity of the zero-order removal of the resultant hologram is proved by expression. The filtering region for the zero-order-removal hologram can extend to the center of its spatial-frequency spectrum domain, which makes higher spatial frequencies on the positive first-order intercepted. In the experiments, the reconstructed amplitude and phase images demonstrate the effectiveness of this zero-order-removal approach and the improvement on imaging resolution.