[en] The electronic structure and optical properties of Fe-F co-doped ZnO are calculated by the first principle under the framework of density function theory with the plane wave super soft pseudopotential method. The supercells of Zn₁₆O₁₆, Zn₁₅Fe₁O₁₆, Zn₁₆O₁₅F₁, Zn₁₅Fe₁O₁₅F₁ are constructed. The band structures and optical properties of ZnO before and after doping are calculated and analyzed. The results show that the co-doped system is easier to form than single-doped system and has higher stability; the covalent property of co-doped systems is weakest which is beneficial to separating the photo-generated hole-electron pairs. The impurity energy series of the co-doped system becomes more denser, and the electrons can easily jump from the low energy level to the high energy level which can improve photocatalytic abilities. The addition of Fe³⁺ results in the Fermi energy level entering the conduction band, producing Mott phase transition and enhancing its conductivity. The main peaks of the dielectric function imaginary part of the doping systems move to the low energy region and the absorption peak in visible light region is obviously increased, showing the co-doped of Fe and F is beneficial to improve the photocatalytic abilities. (authors)