Abstract: The widely use of plastic film mulching technology in agriculture increase crop yields and farmers' income. However, with the extensive use of plastic film, the residual film in the soil is also accumulating yearly, and the accumulated residual film is hard to be removed from soil. If the residual film in soil plough layer can-not be timely treated, it will lead to soil fertility decline, resulting in crop yield reduction and soil contamination. Therefore, it is an urgent issue to remove the residual film from soil, especially in the tillage layer. In order to solve the problem of remnant film recovery, according to the characteristics of the remnant film recovery machine, and according to the requirements of the agronomy of plastic film recovery, a chain-tooth residual film recovery machine is designed and manufactured. It is expected that the transport of membrane-soil, reverse separation of membrane-soil and membrane-collecting process can be completed. In this paper, we studied the influence of the parameters of the reverse membrane-soil separator of the chain-tooth residual membrane recovery machine on the separating effect of the membrane-soil. By analyzing the influence of the parameters on the performance of the reverse membrane-soil separator of the chain-tooth residual membrane recovery machine, the optimal working parameters were obtained, which could provide reference for the follow-up study and optimization of the membrane-soil separator. Aiming at the problems of poor mechanical properties of residual film deposited in the soil plough layer for many years, difficult separation of membrane and soil, and low recovery rate of residual film debris, a chain-tooth residual film recovery machine was designed. The main working parts of the machine are picking up device and membrane soil separating device. The working depth of the machine is 0-150 mm. The pickup device completes the membrane pickup and conveys the soil with the plastic membrane. Then the residual membrane is separated by the reverse membrane soil separating device, and finally the residual membrane is transported to the membrane collector. Taking angular velocity of pickup device, angular velocity of membrane-soil separator and angle of membrane-soil separator as experimental factors, quadratic regression orthogonal test of three factors and three levels was carried out in this study on chain-tooth residual membrane recovery machine with response values of residual membrane recovery rate and soil content. The response surface model of each factor was obtained by experiment, and the influence of each factor on the operation effect was analyzed and optimized. The results showed that the order of the factors affecting the recovery of residual membrane was: angle of membrane-soil separator > angular velocity of pickup device > angular velocity of membrane-soil separator. The order of the factors affecting the soil content was: angle of membrane-soil separator > angular velocity of membrane-soil separator > angular velocity of pickup device; and the optimized results were tested. The results showed that the recovery rate of residual membrane was 81.12% and the soil content was 34.83% when the angular velocity of the pickup device was 42 rad/s, the angular velocity of the membrane-soil separator was 57 rad/s and the angle of the membrane-soil separator was 37°, and the relative error between the experimental value of each evaluation index and the optimized value of the model was less than 5%. The reverse membrane-soil separator can solve the problems of difficult membrane-soil separation and low recovery rate of residual membrane fragments. It can provide a reference for further research and optimization of membrane-soil separator mechanism of residual membrane recovery machine.