Abstract: In response to the current situation where the inspection of liquefied gas cylinders relies heavily on manual operation, which leads to low inspection efficiency and high labor intensity, this paper proposes a design scheme for an automated residual liquid extraction and unloading device for liquefied gas cylinders by improving the existing inspection device. The two key steps of residual liquid extraction and valve disassembly are connected back and forth through a transportation roller table, achieving automatic clamping and flipping during the residual liquid extraction. After the completion of residual liquid extraction, the steel cylinder is automatically transported to the subsequent process through the conveyor roller, and the valve is unloaded after being automatically positioned and clamped at the next workstation. After the valve is unloaded, it automatically falls into the valve recovery device, which can achieve automatic clamping and flipping during residual liquid extraction in groups, and continue to transport the steel cylinder to the subsequent process. This design scheme can significantly improve the efficiency and accuracy of residual liquid extraction and unloading valves, thereby greatly reducing the labor intensity of workers, and providing reference and theoretical basis for optimizing other detection steps of liquefied gas cylinders.