This study aims to optimize the electrocoagulation(EC) process of emulsified oil removal from polymer-flooding sewage (PFS), producing in the oil recovery process and characterized by multiple chemical additives, high viscosity, and high stability. Response surface methodology (RSM) and Box-Behnken statistical experimental design (BBD) were applied to investigate the effects of tilt angles of electrodes, flow rate, and current density as well as the interactions on oil removal and energy consumption. All the experiments were performed in a continuous-flow pattern with an integrated unit combined with reaction and subsequent separation zone. The experimental results suggested that EC technology was very efficient in oily wastewater treatment and was able to achieve 97% oil removal after the system enters into the stable stage with a flow rate of 5.5 L h(-1), applied current density of 18.9 mA cm(-2) and tilt angle 80. At this time, the energy consumption is 3.50 kWh m(-3). Besides, for both of the oil removal and energy consumption, flow rate has the most significant impact, and the current density follows. The results of variance (ANOVA) analysis showed a high correlation coefficient (R-2) value of 0.990 and 0.996 for oil removal and energy consumption, respectively, which ensures an adequate frt of the second-order regression.