In order to solve the problem that the screen holes are prone to clogging during the operation of the drum screen type film and debris separator, resulting in poor screening performance and high debris content in the film, a screen hole clearing device was designed to disturb the flow field at the screen holes by spraying airflow from the nozzle and disrupt the balance of force of the clogged material at the screen holes. The device consisted of a centrifugal blower mounted diagonally on both sides of the drum screen type film separator, a pressure stabilizing pipe and an airflow duct on the outer edge of the drum. The critical air velocity for screen hole cleaning was determined to be 1.151m/s by theoretical analysis, and a positive correlation between fan air velocity and nozzle jet air velocity was investigated by using computational fluid dynamics simulation and curve fitting to determine a final fan air velocity of 9.2m/s. The prototype was designed and tested, and the results showed that 8.28% of the screen holes were clogged and the rate of debris in the film was 7.33%, which was 16.27 and 4.64 percentage points lower than before the installation of the screen hole clearing device. The average jet air velocity of each nozzle was 3.81m/s and the minimum value was 1.22m/s, which met the requirement of clearing the blockage, and the blockage rate of the screen pore and the rate of impurities in the film remained basically unchanged during the continuous operation of the clearing device. The research result can provide reference for the design of various forms of screen hole clearing devices.