Bismuth Ferrite (BiFeO3, BFO) is the only known single-phase multiferroic material at room temperature. Because of its excellent electrical, magnetic and optical performance, it has been an extensively studied material. Most of the BiFeO3 modification studies focus on the metal ion doping in A site，B site, A-and B- site, while the study of the nonmetal ion doping in O site is relatively insufficient. In this dissertation, room temperature solid state precursor method, high-temperature solid-state method and hydrothermal method are adopted to synthesize nonmetal-doped (F, Cl, Br, I, B, C, N, S) BiFeO3 powder. The effects of nonmetal doping on the magnetic and optical properties of BiFeO3 powder are investigated in detail. The magnetic and optical properties of halogen-doped BiFeO3 have been calculated with CASTEP software package of Materials Studio 5.5. The major work can be described as follows: (1) The preparation of pure phase BiFeO3 is one of the hot issues in the research of multiferroic materials. A new technology for preparation of BiFeO3 powders by room temperature solid state precursor method is presented in this dissertation. BiFeO3 micron/nano-powders are synthesized by the heat treatment, raw material types, NaNO3- and polyethylene glycol-assisted control method. The main morphology of BiFeO3 powders synthesized by room temperature solid state precursor method is nearly spherical grain. The grain size of BiFeO3, ranging from 18 to 600 nanometers, can be effectively controlled by different heat treatment and raw materials Owing to the quantum size effect, the optical gaps and magnetic characteristics of BiFeO3 increased with the decreasing grain size. The dispersity of the particulate distinctly improved after NaNO3 was added. The magnetic characteristics of BiFeO3 increased significantly after polyethylene glycol was added. In addition, it was found that the magnetic characteristics of BiFeO3 increased and the optical band gaps decreased with nonmetal ion doping (Cl, N). (2) It is predicted that BiFeO3 has a broad prospect of application in fields such as optical electrode of solar cell and photochemical water splitting. BiFeO3 with visible light absorption and magnetic separation property can be positioned in solution by external magnetic fields.