Abstract: Effect of electrode plates interval, separation voltage, high voltage discharge electrode spacing and charge time on separation efficiency of electrostatic separating device for plastic film residue and seed cotton were studied by single factor experiments, the results showed that electrode plates interval, separation voltage, and charge time had a significant effect on separation efficiency. The separation rate conditions were optimized by response surface analysis at three factors and three levels, and the corresponding regression model was also established. The results showed that when the charge time was 2.71 s, the separation voltage was -30 kV, the electrode plates interval was 14.75 cm, they were best parameter combination and the separation rate was 96.8%. It can provide a foundation for further realizing efficient separation of plastic film residue and seed cotton