In order to improve the efficiency of electrocoagulation of indigo dyeing wastewater, and determine the optimal conditions formation conditions of hydrolyzed metal salts. The Al-Ferron timed spectrophotometry was used to investigate the effect of initial pH value, coexisting anion species, and current density on the distribution of aluminum salts during electrocoagulation. The changes of floc Zeta potential, termination pH, system current and conductivity were also monitored. The dissolution and corrosion of the electrode were observed microscopically, and the electrochemical behavior was analyzed by measuring the electrode polarization curve and electrochemical impedance spectroscopy using an electrochemical workstation. The results showed that the optimal initial pH value range was 6 ~ 7 during the electrocoagulation, when the content of Alb with the dominant flocculation form is higher; the addition of chloride ions inhibited the electrode passivation and enhanced the electrocoagulation reaction rate; the low current density was beneficial to the uniform corrosion of electrodes and the existence of Alb. When the current density was 15mA/cm2, the content of Alb in the system could reach 4.76mg/L, which could produce a good flocculation effect.