Abstract: Supported cobalt azaphthalocyanine (NCoPc/CB) and methyl-substituted cobalt azaphthalocyanine (MeNCoPc/CB) composites were prepared, in which carbon black (CB) was used as a carrier, to solve the problem that polyacrylamide (HPAM) was difficult to be removed in the water. The physical and chemical properties of catalyst and photoelectrocatalytic degradation performance of HPAM was studied in a split photoelectric cooperative catalytic system, with 50 mg/L HPAM aqueous solution as the target pollutant and Na₂SO₄ as the electrolyte. The results confirm that the removal rate of HPAM by the photoelectrocatalysis is not only superior to the photocatalysis and electrocatalysis, but also to the algebraic sum of the two, which shows that the photoelectric combined system has an obvious synergistic enhancement effect. Among them, MeNCoPc/CB composite has the best effect, the pollutant removal rate reaches 76.07%, and the solution viscosity decreases from 8.33 mPa·s to 1.81 mPa·s. The photoelectrocatalytic reaction confirms that the process conforms to the quasi-first-order reaction kinetics, while the reaction rate constants are 6.03 times that of photocatalysis and 3.97 times that of electrocatalysis. Electron spin resonance technology (ESR) confirms that the main active substances in the reaction system are ·OH and O₂·⁻.