Objective: To verify whether the structure design of the conveying part and the collecting part of the cleaning device designed for the surplus grain at the bottom of the cottage warehouse is reasonable, and to determine the key parameters of the device operation, so as to avoid the waste of procurement and manufacturing. Methods: Based on discrete element method, EDEM simulation software was used to simulate the operation effect of the transfer part and the collection part, and the drop rate was used as the evaluation parameter. Results: Through the observation and analysis of the simulation results, it was concluded that the optimal running speed of the corrugated flange belt should be controlled between 0.6 m/s and 0.8 m/s under the condition that the transmission and collection parts could meet the design requirements. Conclusion: The simulation study verifies that the structure of the transfer part and the collection part of the surplus grain cleaning device meets the design requirements, and can provide a reference for the design of the equipment for the transfer and collection of grain materials.