According to the full-potential linearized augmented plane wave method, we calculate the optical properties of In-doped superlattices ZnO. The results reveal that the Fermi energy level enters into the conduction band after doping In. Dielectric function, absorption, refractive index, reflectivity are found to each have a new transition peak near the Fermi energy level. With the increase of the concentration, this transition peak shifts toward the low energy and the spectrum of the peak is the biggest for the two-layer doping case. The optical absorption edge decreases with the increase of doping concentration. Compared with In-doped ZnO supercell, ZnO superlattice has a high transmissivity in the visible light range.