Aiming at the problem of high impurity rate in the recycled residual film, combined with the existing installation (4JMLE-210 agricultural residual film recycling machine), the removal mechanism of light impurities on the film surface was analyzed. The statics and kinematics analysis of light impurity particles in different spatial positions were carried out to determine the conditions for the movement of impurity particles. By analyzing critical conditions, such as ideal collision and throwing capacity, the structural dimensions of the straight pipe section and its outlet section were determined. Using Origin 2018 software, the movement track of the impurity particles left from the upper and lower limit positions and the ideal curve of the throwing arc were plotted, and the trapezoidal section was determined at the outlet of the throwing arc section. Finally, trial-produce prototype, and a field test was carried out on the performance of the machine by selecting the impurity rate in the recovered residual film as the test index. The results showed that when the forward speed of the machine and the rotating speed of the cutter roll were in the range of 5.4–5.8 km/h and 1440–1460 r·min−1, the light impurity rate and working efficiency could keep a good balance. The light impurity rate in the recovered residual film was between 10.9% and 31.4%, and the average light impurity rate was around 18.7%, which met the design and application requirements.

In order to solve the problem of high straw content in recovered residual film and the low rate of qualified straw crushing in combination with a front-mounted cotton-straw-crushing device, the cutting and crushing mechanisms of cotton stalks were studied based on ANSYS/LS-DYNA. The height h and dip angle α of the fixed blade were determined to be 30 mm and 75° through a finite element analysis. On the basis of the device design, explicit dynamic models of the cutting and crushing of a single cotton stalk were established based on ANSYS/LS-DYNA. The results of the dynamic analysis revealed the cutting mechanism of the cotton stalk, and the influences of the cutting edge angle γ and front baffle height h1 on cotton stalk cutting were studied by using single-factor simulation tests. An edge angle of γ = 45° and a height of h1 = 265 mm were determined. Meanwhile, the mechanism of cotton straw crushing was revealed, and the motion states of the straw were studied at different times. The results of the simulation experiments on the influence of the cutter shaft’s rotational speed showed that with an increase in the cutter shaft’s speed, the rate of qualified crushing and the removal rate were both increased. At the design speed of n = 1800 RPM, the rate of qualified crushing was 84.6%, and the removal rate was 95.1%. Then, field experiments were carried out. The test results were as follows: the stubble height was 8.0 cm, the rate of qualified straw crushing was 91.8%, the clearance rate of film-surface impurities was 92.3%, and the film content was 3.6%, which met the working quality requirements (not less than 85%) of NYT 500-2015: “Operating quality for straw-smashing machines”.