Since the pollution of algae blooms has seriously affected drinking water safety for a long time, it is urgent to develop effective techniques to control and reduce algal reproduction. By using Pt/Ti anode and ACF/Ni cathode, effects of the parameters such as cathode materials (ACF/Ni and stainless steel) as well as the concentration and valence state of iron added on the electrochemical removal of algae were investigated to explore the removal efficiency and mechanism of algae in the Pt/Ti-ACF/Ni-Fe²⁺ electrochemical system. Results showed that under the conditions of Fe²⁺ concentration of 0.05 mmol/L, current density of 50 mA/cm², inter-electrode gap of 1.0 cm, initial pH of 6.0, and initial algal cell density of 1.2×10⁹-1.4×10⁹ cells/L, 93% of the algae cells were removed in 15 min. Based on the analyses of ferric ion concentration, H₂O₂ concentration, and pH in the experiments, indirect detection of ·OH, FTIR analysis of ACF, SEM images of algae, and ACF/Ni and BET analyses of ACF, mechanism of algae removal was revealed in the Pt/Ti-ACF/Ni-Fe²⁺ system. H₂O₂ was generated efficiently through electrochemical reduction on the surface of the ACF/Ni cathode, the iron in solid phase generated during the reaction was precipitated on the surface of ACF/Ni cathode with the electrochemical reduction of Fe(Ⅲ) to Fe(Ⅱ), and meanwhile ·OH would be generated in the Pt/Ti-ACF/Ni-Fe²⁺ algae removal system. Heterogeneous and homogenous electro-Fenton processes were the main mechanism in the Pt/Ti-ACF/Ni-Fe²⁺ algae removal system.