As a kind of recyclable material, the residual film can be recycled and the pollution can be reduced only by separating the residual film from the impurity. However, the residual film, cotton core, cotton rod and other impurities after mechanical recovery are entangled seriously. So it is difficult to separate them, even to make use of resources. Direct incineration or centralized stacking of recovered residual film results in great waste of resources and serious secondary pollution. In order to solve the problem of high impurity content in waste film recovery, a spiral impurity cleaning device was put forward according to the working principle of the profile mode residual film collecting straw crushing combined machine. The structure and working principle of the spiral impurity cleaning device were introduced. The key parts of the device were analyzed and the parameters were designed. The three-dimensional discrete element model of cotton rod, soil and spiral impurity cleaning device was established by using EDEM software. The cleaning and conveying process of cotton rod and soil mixed particles was simulated. Taking the structure parameter pitch, the diameter of helical blade and outlet clearance of the spiral impurity cleaning device as test variables, orthogonal simulation experiments were carried out with mean particle velocity, average longitudinal particle velocity, mass flow rate and total helical axis torque as dependent variables. The influence of three test factors on each index was analyzed, and the order of primary and secondary factors was analyzed. The test results showed that the optimum parameter combination of the spiral impurity cleaning device was as follows: screw pitch was 200mm, screw blade diameter was 200mm, and outlet diameter was 220mm. Under the combination of these parameters, the device was made and assembled with the profile mode residual film recovery straw pulverizing machine. A performance test was carried out in the cotton field. The results showed that the cleaning effect of cotton rod and soil by the equipment was in accordance with the design requirements, and residual film and impurity separation rate was 89.51%.