The metal Ce was doped into Bi₂O₃ Based on the electrospinning technology, and a novel linear composite catalyst with enhanced photocatalytic activity was prepared. The effect of different doping ratio on the modification of Bi₂O₃ was studied by XRD, SEM, TEM and UV vis-DRS characterization and analysis. And the home-made photocatalyst was applied to treat dye wastewater in the liquid phase, with degradation of methyl orange as the goal, the research results show that metal Ce successfully doped into the Bi₂O₃ replaced the part of the Bi lattice, the doping ratio of 0.25 possess best visible light catalytic activity, the absorption edge redshift is the largest, and the band gap width is 2.22eV, The catalytic degradation rate of MO under visible light irradiation reaches 98.81% in 90 minutes. The photodegradation process conforms to the first-order kinetic process, and the photocatalyst property is stable.The research results provide basis and support for the modification and development of Bi₂O₃, the development of new composite photocatalytic materials, and the photodegradation of organic pollutants with poor biodegradability in the water treatment field.