The electron donating properties of benzidine units were enhanced by substituent modification, then by copolymerizing then with benzaldehyde units a group of conjugated polymers with donor acceptor structure were synthesized based on the simple structure design. The structures of the monomers and polymers were characterized by H NMR, FT-IR and XRD, which showed that the target products were successfully prepared. The photoelectric and electrochemical properties of the copolymers were tested by UV-vis, UV-vis-DRS, cyclic voltammetry, chronopotentiometry, AC impedance and cyclic performance tests. The results show that the conjugated polymer P3 prepared by introducing methoxyl group has higher conjugation degree and better crystallinity, and its optical band gap E_g^opt is 2.09 eV. This sample has higher HOMO and lower LUMO values, which are -5.15 eV and -3.06 eV respectively, showing better redox performance, and correspondingly also showing better electrochemical capacitance characteristics. At 0.3 A/g, the first discharge specific capacitance of P3 tested by constant current charge and discharge reaches 1030 F/g, and remains at 530 F/g after 700 cycles.