Deep silicon removal of super-heavy oil produced water was developed through electrocoagulation by using aluminum plates as cathode and anode. The influence factor of electrocoagulation was optimized. Then the optimum pH value，current density，polyaluminum chloride（PAC）and anionic polyacrylamide（PAM）dosage were obtained. The results showed that single electrocoagulation could not achieve deep silicon removal. Electrocoagulation together with PAC and PAM had a synergistic effect on the removal of silicon from super-heavy oil produced water. Under the condition of 200 mg/L PAC，8.0 pH value，10 mA/cm² current density and 50 mg/L PAM，the removal rate of SiO₂ increased with increasing electrocoagulation time，but the increment decreased. When the electrocoagulation time was 13 min，the SiO₂ content in electrocoagulation effluent was 20 mg/L，meanwhile the SiO₂ removal rate was 92%，which achieved deep silicon removal.