In view of the differences in density, suspension speed and flow characteristics between residual film and soil, straw and other impurities, a suspension separation method based on EDEM-Fluent was proposed. Three methods for measuring the suspension separation velocity of residual film, cotton straw and soil mixture, namely theoretical calculation method, simulation analysis method and bench test method were introduced. Three methods were used to determine the residual film suspension separation velocity. The EDEM-Fluent coupling method was used to simulate the suspension separation process of residual film and impurities. When the total mass of soil and straw in the three residual film mixtures was 40% (30% of soil), 60% (50% of soil) and 80% (70% of soil), the simulation 〖JP2〗numerical range of residual film suspension velocity were respectively 4.77～5.83m/s, 4.89～6.46m/s and 5.31～7.40m/s. Determination of suspension separation velocity of three residual film mixtures by bench test were respectively in the range of 4.67～5.77m/s, 4.88～6.37m/s and 5.29～7.22m/s. The relative error range between the software simulation and the bench test was 0.77%～4.79%, which verified the feasibility of measuring the suspension separation velocity of the residual film mixture based on EDEM-Fluent coupling method. The impurity in the mixture changed the shape variable and motion characteristic of the residual film, thus affecting the suspension velocity and position of the residual film. The lower limit of the simulation value of the residual film suspension separation speed was significantly different from that of the bench test, so the lower limit value of the simulation and bench test results was selected to calculate the correction coefficient, and the average value of the correction coefficient of the residual film suspension separation speed was 0.95. According to the field experiment, the optimal wind speed for separation of residual film and impurities and recovery of residual film was 5～7m/s. At this point, the recovered film contains impurities rate and film recovery rate were 20.47% and 83.62%, respectively.