Objective: Aiming at the low degree of mechanization, automation and intelligence in the cleaning and collecting process of the surplus grain at the bottom of the granary, a cleaning and collecting device for the surplus grain at the bottom of the silo was designed and manufactured. Methods: Based on simulation and numerical calculation, the structural strength analysis and optimization of the reliability of the key components of the cleaning and collection device were carried out, and verification experiments were also carried out through the manufacturing prototype. Results: The cleaning device designed in the experiment can clean the surplus grain of the same area and density, the cleaning speed is 10 times that of a single worker, and a single cleaning can collect more than 90% of the surplus grain, which can effectively save manpower. Conclusion: The device has high practicability and can be promoted in relevant grain depots in China.